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Is anyone out there happy with their tankless water heater?

Posted by fiddleddd (My Page) on
Sat, Nov 6, 10 at 13:12

I've just spent the past 2 hours reading posts about tankless water heaters here on GW. We WERE all set to have a Bosch system installed next week. But after reading all of these reviews, I'm going to tell the plumber to hold off.

The preponderance of comments have been negative about tankless units. Is anyone happy with theirs? And I haven't read a single good comment about the Bosch....something about a bad design and water flow.

Our plumber has done a great job so far on a complete house renovation. He says he has installed tankless heaters before, and he initially recommended Rheme. Then our plumber supply rep who is supplying all of our plumbing needs for the house recommended Bosch. When we asked the plumber about Bosch, he said that would be good too. So go figure......does anyone really know???!!!

I might add that we are down-sizing from a 3600 to 1800 square ft. house (including basement). We decided to go tankless because of space constraints and the fact that we'll be traveling half of the year.

All of our runs are short. In fact, the water tank will be close to both bathrooms and right under the kitchen sink.

Please help, and let me know if you think we're making a mistake by installing a tankless.


Follow-Up Postings:

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RE: Is anyone out there happy with their tankless water heater?

FWIW...I'm not an expert so have no particular details, but...BiL has Bosch unit installed three years ago in a house a short distance from my own. 2,000 sq. ft. He did the install himself. It's been flawless. He and wife have been very satisfied.


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RE: Is anyone out there happy with their tankless water heater?

asolo.....thanks so much. However, this is quite literally the very first good thing I've read about the Bosch. I hope I get some feedback from others who have the unit or know something about it. I appreciate you passing along that info.


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RE: Is anyone out there happy with their tankless water heater?

I have spent about 2 years trying to decide if that is the way to go or not. I've talked to 4 plumbers, one who will not install tankless at all, two who don't recommend them but would install if I insisted, and one who advocates them. None of them would sell a Bosch, calling it a "big box store" product rather than a professional grade product that a plumber would be willing to stand behind. We actually went to the house of the fourth plumber to see his unit in action and talk to his wife about how well she liked it.

A couple of things we learned from them.
1. It operates differently than a tank unit, and you have to get used to it.
2. It is best suited to a household that uses lots of hot water. (he has three teenage daughters and a spa tub)
3. It will probably not pay for itself in its lifetime, but it does cost less to operate than a tank heater.
4. If you have propane instead of natural gas, and you are paying over $3 per gallon, it might pay for itself.

Because of installation complexity it was going to be expensive to install in our house, so we stayed with conventional tank system. But I like the principle of tankless.


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RE: Is anyone out there happy with their tankless water heater?

ramona1976......thanks so much for sharing this with me. Our situation makes it easy to install a tankless unit because we have virtually changed EVERYthing in the house. It's almost like new construction actually.

But so many people seem to have trouble with them.....I wouldn't want to spend all the $$$ for one, and then be so frustrated with it that we would have to revert to a regular tank water heater.

Furthermore, our water heater in our current home is in the basement, and twice in the 25 years we've lived here we've had slow leaks that we didn't catch for awhile because we don't go to the basement very often. So we were kind of looking forward to not having another tank unit in a basement (which is where ours will be located in the 'new' house).

We are not considering the tankless unit for the cost savings, or even for environmental reasons. It's pure and simply a space issue for us. We love the concept of tankless, but I guess we need to be convinced about it.

If more people like you answer, maybe I'll start to acquire a consensus. Thanks again!


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RE: Is anyone out there happy with their tankless water heater?

We have had our Noritz natural gas tankless for almost two years. We decided to get the Nortiz because it is neater and smaller, about 18" x 24" box with pipes and lines running in and out of it. It is mounted up about chest high on the side of the house with a remote controller inside the house to raise or lower water temp. I'm sure we are saving gas, but you cannot tell by looking at the gas bill because it fluctuates anyway. The heater works fine.

One downside of the tankless is that you have no emergency water supply should you need it. This is important for people who live in earthquake zones or anywhere that the water supply could be cut off. Also, the Noritz makes a little humming sound when it works, which noise lasts a few seconds after you turn off the hot water, not much louder than the burner igniting under a regular heater. But if you are sensitive to noises, you might not like it.

Here's what happened this past week. Friday--no hot water. Plumber came Sunday. Could not fix. Two more plumber visits and still could not figure out what was wrong. Is it the flow sensor? Is it the motherboard? Phone calls to the Noritz company. Head scratching. Finally, on the 4th visit and after 6 days with no hot water, the plumber found a dead SPIDER inside the heater blocking the flow of gas. Took the critter away, and we have hot water again.

Couple other things: the Noritz is supposed to be "descaled" every year or so (run vinegar through it basically). But if the plumber does it, it costs quite a bit. But you can buy a kit and do it yourself.

Also, if you are not going to use it for a long period of time, the water should be drained.

We are not sorry we got it because it works well, but I'm just not sure that any advantages make it worth the expense.

Susan


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RE: Is anyone out there happy with their tankless water heater?

socks12345......you confirm what I'm discovering about tankless. They're quirky to say the least, and even experienced plumbers scratch their heads over how to service them.....all the more reason I want to buy a reliable one to begin with! :-)

I hadn't read anywhere about tankless heaters making a noise.....hmmmm...I'll ask about that. But the Noritz being smaller certainly sounds good because we have space constraints. I'll check into them. Thanks for your input!

A spider, eh? Crazy!!! And how much did that diagnosis cost you? :-)


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RE: Is anyone out there happy with their tankless water heater?

I've been using an electric tankless unit [yes, I know, I can hear everybody run screaming away] for a couple months shy of 6 years and am quite happy with it. No trouble thus far, and I've not descaled it although I suppose that probably should be done.

Regards to the comment that tankless is best-suited to households that use a lot of hot water ... why would that be the case? Being a single person household, I may go three days at a stretch without using any hot water at all (yes, I hear more people running away ... but I work primarily from home sitting at a computer, so I don't get sweated and need to bathe daily). With the tankless unit I'm not keeping 40 to 50 gallons of water heated for 3 days until I need it ... hot water doesn't even exist until I turn on a tap. I also don't have to keep a large volume of water heated to 130°F to 140°F in order to have sufficient reserve capacity if I want to use my Jacuzzi bath. I have the tankless set at 104°F which is perfect for showering and suitable for washing clothes at 'warm' temperature. I can raise the setpoint temporarily if needed. My dishwasher heats its water internally so no need to raise the temp for that chore.


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RE: Is anyone out there happy with their tankless water heater?

fiddleddd:

I do have one and I'm very happy with my Rheem unit. I've had it about 3 years now and installed it myself.

That said, they are different than a tank heater. Water does take about 3 seconds longer to get hot than with a tank. It does make some sound when it's working. You also need to have a plumber who knows what he's doing when sizing and deciding what unit/how it's installed.

Quirky isn't what I would call them... just different. Plumbers and homeowners have been used to tank water heaters in the US... but they have been using these tankless units in Japan and Europe for some time.

A few years ago when I was doing my research, Bosch was the brand that was available at the home improvement stores. They were not the quality that they should have been - probably in order to meet a price point. As it turned out, I think they did a lot of damage to the image of tankless heaters.

One of the Bosch units in particular was a problem - the Aquastar. It used the water flowing through the heater to generate a spark to light the heater. It was a source of endless complaints.

Bosch may have fixed their problems, but there's no reason to go with them since there are systems out there that have had consistently better quality.

Other than the cost of the unit itself and the need for an outlet, there's no reason that a tankless install that's properly designed needs to be expensive. You can install the venting through the wall, (rim joist in my case) so that there's little vent cost. It doesn't require two people to install and it's no more difficult to rough-in than a standard tank heater.


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RE: Is anyone out there happy with their tankless water heater?

Rinnai tankless here, and I LOVE IT! We have had it for seven years and really love the fact that we never run out of hot water, even when the house is full to overflowing with holiday company.

About four months ago, the heat exchange unit developed a pinhole leak. I assumed I would have a problem getting the company to fix it. However, without so much as a whisper of a complaint, they replaced the entire heat exchanger. I only paid minimal labor. I am so impressed with how they back their product.


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RE: Is anyone out there happy with their tankless water heater?

Fiddleddd--can you put a gas tankless inside? They do vent out a bit at the top, for ours anyway. Maybe they have to be vented to the outside?

I think we ended up paying around $220 for 4 visits, descaling and finding the spider. DH was unhappy with that, but the company lost money with all those visits. By the way, it was a company authorized by Noritz to do tankless installs and repairs.

There is nothing to get used to with a tankless. You turn the handle, hot water comes out!! The only thing different for us is the need to descale annually.


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RE: Is anyone out there happy with their tankless water heater?

Socks12345:

They make gas tankless that mount inside as well as a separate model that mounts outside and doesn't need a vent. The inside models have a sealed vent connection.

The outside version is most appropriate where it doesn't get really cold. Not sure where the OP is located - but if the winters are mild, outside in the stud space of an exterior wall is an option.


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RE: Is anyone out there happy with their tankless water heater?

I have installed several tankless heaters for customers over the last few years, most recently these three: An older couple who don't use a whole lot of hot water, a family with several kids who use lots of hot water, and in a new house where space was limited. All are very happy with their installs and currently have had no problems known to date.
Ditto everthing that other posters here have said. They are more expensive than tank type water heaters, heater + installation, especially when changing from a tank type in an older home. They will probably never pay for themselves with the little energy they save verses the amount of energy used by a tank type.
The manufacturers suggest the once a year flushing, to reduce the build up of scale in the exchangers. The theory is the accumulation will reduce flow and effeciency of the unit.
Getting one serviced can be a problem, as someone talked about above, not all of us are familiar with them, and usually require a lot of tech experience in dealing with them. They all have their own parts and anyone that services them needs to carry the parts. We refer out or water heater servicing because of the tech knowledge needed and the stock of parts required.
Sometimes there is a noticeable reduction in flow of hot water, due to the fact the water needs to flow through an exchanger and flow slow enough for it to heat.
The positives I can verify, the little space that they require, the endless hot water. The negatives can easily be overlooked if the positives are greatly desired.--The Captain


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RE: Is anyone out there happy with their tankless water heater?

After getting home from a long day at work, I'm thrilled to read all of these responses!!! Thanks so much!

I'm developing a philosophy about tankless water heaters. That is....nobody gets really excited about such things as tankless water heaters (or any water heaters), so as long as it's chugging along doing what it's supposed to do, nobody thinks about it. On the other hand, when something DOES go wrong, it can really disrupt your daily lives. So then of course people write to complain about it. Those who are satisfied just quietly take it for granted and don't write singing the praises of tankless water heaters. :-)

So I'm most appreciative of those of you who have taken the time to write.

dadoes.....sounds like you have a sense of humor! :-) I won't tell anyone you don't shower every day (I don't either....dries my skin out!). But I do see the benefit of not having to keep a full tank of hot water, especially when there are only 2 of us now, and we're gone for extended periods of time.

jakethewonderdog.....actually the Bosch we were going to get was coming from a high-end plumbing store, where they supposedly carry the top brands. There may be a lower model Bosch carried at the big box stores, although our local stores don't carry the Bosch line at all. Thanks for explaining in simple terms for me to understand why the Bosch had so many problems. That's what I've been reading elsewhere as well.

aliceinwonderland.....Thanks for your feedback on Rinnai....they sound like a great company. I haven't researched them yet.....do you happen to know if they're more expensive than most? Another brand I've heard good things about is the Rheme. Did you consider them at all?

socks12345.....Actually, we ARE installing a gas tankless inside in the basement. The vent is already run. It vents to the outside....the intake and exhaust are combined so there is only one vent to the outside. I hope that vent will still work now that we've decided against the Bosch. I assume any tankless will need such a vent though.....for gas, anyway.

jakethewonderdog.....we're in Indiana, and we can get some brutally cold winters, so we decided to put ours inside and vent to the outside.

captainbob.....good info there....thanks! So there ARE people out there happy with their units, which does my heart good. We really wanted to use tankless because of space concerns. Do you have a particular brand of tankless you can recommend? What did you install in those 3 instances? I'd be curious. My 2 biggest considerations are 1)will the thing work and 2)if something does go wrong, will the company stand behind their product?

Thanks again to all of you!


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RE: Is anyone out there happy with their tankless water heater?

jakethewonderdog......I stand corrected. It appears that Lowe's does indeed carry Bosch brand. When we first looked there about a year ago, I don't remember them carrying Bosch, but they do now....at least online.


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RE: Is anyone out there happy with their tankless water heater?

jakethewonderdog......I stand corrected. It appears that Lowe's does indeed carry Bosch brand. When we first looked there about a year ago, I don't remember them carrying Bosch, but they do now....at least online.


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RE: Is anyone out there happy with their tankless water heater?

We've had our Myson tankless for going on 14 years now. It's great. There are a lot of newer innovations out there for tankless, but our is a simple unit with zero electronics. Uses a pressure sensing diaphragm to trigger an igniter and, presto, we have hot water. We even have hot water during power outages, which with the newer units you'd have to have a generator for the electrical connections in order to have. We've had to replace that diaphragm exactly once in 14 years, at a cost of under $10. Our water quality is extremely good (they bottle it to sell) so we've only descaled it once. Really didn't even need it then. We installed it ourself, as at that time, there was no one in town who had even heard of tankless. YEs, we'd do it again. In a hearbeat!


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RE: Is anyone out there happy with their tankless water heater?

We have a Noritz that's been in for ~5 years without a problem. Brand wise, I'd look there or at Rinnai, Takagi, or Rheem. Have no idea about current Bosch, but I read the complaints here about the HD Aquastar.

Ours is mounted outside to be near the two bathrooms it serves. I put it in during a remodel, and we kept our tank heater to serve the kitchen and laundry room. There's a closed valve between the two sides that I can open if either heater quits working.

The outside option is great, but we're in GA. Saves on the vent cost, doesn't take up floor space, and is close to the point of use. You still have to run a bigger NG pipe than you would for a tank unit (larger instantaneous flow). I have a self-regulating heat tape and insulation on the exposed piping that I'll plug in here soon and leave that way until maybe March after the last freeze.

If you already have the vent pipe run, I would just be sure that it's the right kind. You can't plug one up to an old galvanized vent b/c the condensation/corrosion will do it in. That's a conceptual problem folks have with retrofits. But if you're looking at a high-efficiency heater of either variety, they've probably already run the SS vent piping.

Ours is set at 105F which has proved plenty hot for showering year round. My only complaint is that the incoming water temp gets high enough in late summer that the thermostatic valve in my shower runs the HW flow down low enough after 5 min or so to cut the heater off. Makes for a built-in shower timer. ;-) And I refuse to pull out the flow restrictor, since we are all about water efficiency.


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RE: Is anyone out there happy with their tankless water heater?

live wire oak.....wow! That's a pretty glowing endorsement! I've never even heard of a Myson brand, but I'm sure you're right......all tankless heaters today probably have more sophisticated electronics involved. I hope we have as good of luck with ours as you've had.......although we still haven't decided what we're going to get......it just won't be a Bosch.

thull.....fortunate for us, we have all new plumbing so nothing needs to be retrofitted. We did, however, already put in the vent for the Bosch system. Depending on what other unit we decided on (we're thinking possibly Rheem),we may need to change that around a bit. But it shouldn't be too big of an issue. Your last paragraph is exactly what I'm afraid of. I hate cold water when I'm showering, and I want to ensure that we don't have the cold/hot thing happening that so many people describe. Yet we're like you.....fairly environmentally friendly and like to conserve water. So we'll see. Thanks for your thoughts.


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RE: Is anyone out there happy with their tankless water heater?

The problems with Bosch Aquastar are a basically a result of poor product marketing.

Yes, the minimum flow rate is a bit high for a tankless unit. But that is really the only unique design flaw with the Bosch Aquastar.

The negative experiences so many consumers report about the Bosch Aquastar are really problems with the installation.

For years Lowes and Home Depot have sold the Bosch tankless water heaters. But they do not sell the right vent pipes. They do not have any knowledgeable people working there. They do not have the valve kits needed to provide a way to flush the scale out of the boiler.

So many DIY people and Handy-people have bought Bosch tankless heaters from these box-stores and got them installed incorrectly. I was one of those people about 6 years ago. Within a year of instaling it wrong, I started having major problems and soon became a very unhappy customer. I was ready to throw the thing away and get another storage tank water heater.

But my stubborn nature persevered. I learned about the way Tankless heaters are different and how you have to make some plumbing adjustments to get the thing to work right and provide maximum comfort.

A small 5 gallon tank heater, installed in line after the tankless heater is the best way to achieve total comfort. The cold water that comes out during the first few seconds is mixed in with the 5 gallons of hot water in the storage tank. This makes washing dishes and hands WAY more comfortable. My cold water temperature is usually about 50 deg, so you can imagine how cold that feels when you are expecting hot.

The small heater does not use much energy because it is refilled with hot water from the tankless unit. I keep the thermostat on the tank heater set at about 105, and the tankless heater is set above 120. The small tank doesn't have to do much heating at all, it just keeps it warm.


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RE: Is anyone out there happy with their tankless water heater?

I've had two for about 4 years now. The are both in the attic above the second floor. no problems so far and we all love the endless hot water.


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RE: Is anyone out there happy with their tankless water heater?

aidan m......good info! I'm sure that improper installation is responsible for most of the problems. Thing is.....I'm not sure how many licensed plumbers really understand the technology and can put one in correctly. But it's nice to know about your idea of the small back-up tank. We'll have to remember that if we have any trouble.

klcox.....and could you share what brand you have? Have you ever had it serviced? Thanks for sharing! I'm feeling more and more encouraged from these responses.


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RE: Is anyone out there happy with their tankless water heater?

fiddleddd: We have mostly installed the Rinnai tankless 180,000 btu unit, recommended for 2-3 bathroom homes. We haven't installed many of these units, maybe half a dozen in the last 5 years. What seems to keep people from going with tankless is their high initial cost of the unit & installation.
As I mentioned before, all of our customers are satisfied with them, what feedback we have had back, and we haven’t had any service calls on them going back 5 years now. I believe part of it is due to the fact our customers were aware of the differences of these verses tank type going into it.
A few years ago Rinnai started a pretty aggressive advertising campaign, with advertising done by the late Paul Harvey and others, and factory reps working wholesalers and plumbers like myself to promote their products. They were the ones I believe that started the interest in tankless.
My opinion on Rinnai is they seem to be as good as any of the tankless out there now, offering 12-Year Warranty on Heat Exchanger, 5 Year Parts, 1 Year Labor for Residential Installations. They seem to have good support and have been setting up Rinnai Authorized Service Providers in areas all over the country. We are a registered Rinnai dealer and were asked to become a service provider, but we figured with the small amount of these we have installed verses the amount of training and the parts that we would have to stock and keep updated on it wasn’t worth it. Our line of standard tank type heaters we don’t even service; we refer out service on them as well to a company that is all they do is service water heaters. They have the parts in their trucks, and have techs that is all they do is troubleshoot & repair water heaters. As complicated and high tech they are getting these days, it is pretty much the way it has become.
I would recommend what ever tankless you go with, do your homework and investigate their service support and make sure they are set up with parts and can handle the warranty paperwork.
The small tank I seen mentioned above is for eliminating what is called the 'cold water sandwich'. It helps with that first few seconds of water. This was something that our current customers didn't seem to be concerned about, however something to think about. Some newer tankless designs, like Navien, for example, have a built in buffer tank and circulate the water internally between it the heat exchanger to eliminate that 'sandwich'. Just remember the more things that you add, the more it will cost and the more chances for something to give you trouble.


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RE: Is anyone out there happy with their tankless water heater?

We've had a Rinnai for about 1.5 years. The HVAC guy actually installed it when he put in our new furnace. It never made sense to me to have a giant tank the garage that just heated up water to have it sit there. A waste of energy in my book. Plus, I hated running out of hot water. We have had zero problems with ours. I love the digital water temperatur control. Even I can operate that! I didn't do one scratch of research on brands so I have no idea on any others, but we love our Rinnai and would do it again.

I'm really glad now that we did it because I have a new 100 gallon bathtub sitting in our half-framed new master bath. I know it will get filled with hot water!


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RE: Is anyone out there happy with their tankless water heater?

We installed a Takagi-1 in 2001, and have had no trouble with it. As far as cost, we noticed an immediate 25% reduction in our monthly gas bill, but the real savings is not having to replace a tank-type water heater every 8 to 10 years. Even the best tank-type water heaters fail in 12 years. The Takagi should last 20 to 25 years.

The one thing you need to be aware of is that the more simultaneous users of the hot water, the colder the water gets. So we don't run the washer while taking a shower.


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RE: Is anyone out there happy with their tankless water heater?

captainbob....I've researched the plumbers in our area who are Rinnai certified dealers, and I'm going to see who sounds most impressive and knowledgeable on the phone.....then probably go with a Rinnai....thanks for sharing your experience.

breezygirl.....so you don't have the small tank mentioned above to prevent the 'cold water sandwich'? I'm glad to hear it's working so well for you. I hope we have the same experience!

ihalsema....Yes, I've read some good things about the Takagi, although I haven't found as much info on them as I have the Rinnai. I've read many good things about the extraordinary customer service for the Rinnai, so I think we're going to go with it. To me it's worth it to know that if something does go wrong, someone will 'listen'. :-)

It's just 2 of us now, and since we've always had a regular tank water heater, we're used to not doing laundry or running the dishwasher at the same time we take a shower. So we'll probably continue that habit and hopefully won't have trouble with the cold water problem. Thanks!


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RE: Is anyone out there happy with their tankless water heater?

We don't have a small tank- there was an article in Fine Homebuilding about it a few years ago. Haven't had too much problem with cold water b/c my wife and I either run the hot water or not. We occasionally have problems when getting the munchkin clean due to stopping/starting the water and then having to wait. But I'm in no rush to put the extra tank in.

Our Noritz heater is set at 105F and that has worked great. Part of my reasoning for doing that is that hotter water is just going to cool down faster (and you're wasting gas heating it to just dilute it later). We have copper piping, and even insulated the water loses temperature quickly. We also just use it in the bathrooms; the dishwasher is the only place where I might want hotter water.

One other adjustment- when I shave, I just crank on the hot tap until I get warm/hot water. Then I close the drain and let a 1/2-gal of water or so sit in the bottom of the sink and cut off the tap. I used to let a trickle of hot water flow the whole time, but it never would've been enough to cause the tankless to turn on.

Here is a link that might be useful: Fine Homebuilding article teaser


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RE: Is anyone out there happy with their tankless water heater?

We have a Takagi that is about 10 years old. I can't attest to it's performance before we bought our house about 30 months ago, but up until recently we have been very happy with it! Great when we have guests - you can take one shower after another and not run out of hot water or take a shower after just doing a load of laundry. Unfortunately, we are currently having problems but have been told that it is not an issue with the water heater itself. Still have not determined the culprit.


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RE: Is anyone out there happy with their tankless water heater?

I have a Rinnai tankless, installed about 3 years ago. It is located outside, on the side of the house. The controller for it is in the house, in the laundry room. We adjust the temperature all the time. Dh likes his baths HOT, so will turn the water to 120. I wash dishtowels at 140. In the summer we keep it around 102 or so for regular use, in the winter 110 is good for most uses. I have not descaled it yet and I guess I should look into it as we have very hard water here.


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RE: Is anyone out there happy with their tankless water heater?

I know this thread is a couple of days stale; however, being a convert from tank to tankless, I do have a comment or two. First, if you are doing research then you are obviously interested in the "new" (actually old) technology. There are major benefits to tankless and some drawbacks. The benefits have already been said, but then again, there is the 1500.00 govt credit as well. The drawbacks so far: 3 showers at the same time will reduce your flow rate (or, if not 3 showers, then 3 x hot water uses). It's an electric/gas or electric/electric appliance. Lose power, lose hot water. Purchase a UPS for those days you "might" lose power. That's it on my experience.
I relied heavily on the Energy Star program (link below) on each brand, EF, BTU, Warranty. Then I researched each brand. In the end, I ended up with the Navien NR-210A. It fit the bill for what my criteria was. Granted, I'm new at this, but so far we are just tickled. Haven't seen our gas bill yet, but we expect some reduction. We set ours at 130 degrees.

Here is a link that might be useful: Water Heater, Whole Home Gas Tankless for Consumers


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RE: Is anyone out there happy with their tankless water heater?

"I have the tankless set at 104°F"- I suppose that's relatively safe since it doesn't store hot water, but I don't know if there's still a Legionella risk with the water that remains in there.

Storage HW heaters should be kept at 60C/140F to mitigate the risk of Legionella. From an environmental/kid safety point of view they say 50C but you can't win. I suppose the compormise is mixing valves to regulate the temp.

As for the tankless, most of the new construction with tankless use Reem here in Canada, but to some extent, it may be because they're cheaper, many of the houses are spec so the cheaper the better (balanced with the need to provide new-home warranty I suppose)

I've heard tankless are not successful without 3/4" lines, so that's something to keep in mind. As for the risk of flooding with the tank heater, 1) if you go for a tank, make sure there's a drip tray under, whether it's required by code or not, and that the heater either has legs that raise it above the tray level, or set the heater on bricks so the bottom does not rest in any water that might connect in the tray (which must be connected to the floor drain)

Option 2 is a water alarm - if you have a security system they can usually add a water sensor, that's the "gold standard" with monitored systems so you'll get a warning even if you're not home, or a plain battery-powered buzzer type that's only $20 or so at your hardware store.


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RE: Is anyone out there happy with their tankless water heater?

Yes, I'm still following this thread, and I've been 'listening'. :-) It has taken us awhile to find a plumber really knowledgeable about tankless water heaters. Finally! We called the gas company to inquire about a few things too.....just to be sure. This plumber used to use Rinnai brand, but has recently switched to Navien. He says both are good, but he likes the Navien a little better. We'll need 2 pressure regulators, one for our gas furnace, and one for the water heater.

There will mostly be only 2 of us sharing the living space, so it will be rare to need more than 2 sources of hot water at any one time. After all, we're used to staggering our hot water usage anyway after having a big family and needing to conserve our hot water in our standard tank water heater.

Thanks for the suggestions and sharing your experiences. Particular thanks for the links...the Energy Star link is a great resource. I'm anxious to show that one to my husband.

Thanks, again! I'll report back after we get it installed, which may be after the first of the year. We won't be actually moving over to that house until possibly next spring, so we're in no big hurry!


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RE: Is anyone out there happy with their tankless water heater?

IMO, the concerns about running, or rather, being unable to run, multiple hot water tasks simultaneously is overblown. While it's true that I'm a single-person household and rarely run more than one task at a time, I once did a test by turning on several faucets at the same time (kitchen and three bathroom sinks, and probably two showers) and ALL of them had heated water, NONE of them ran cold.

Consider that even if two or three tasks run at the same time, all of them don't necessarily run at full-flow or require maximum water temp. A dishwasher filling typically runs for a couple mins at most. Washing machines vary on how much water they take for a fill ... HE or non-HE machine, size of the load, and temperature setting are factors that come into play. I don't run my shower at full-force for that matter, my dad "learned" me years ago not to do that.


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RE: Is anyone out there happy with their tankless water heater?

"'I have the tankless set at 104°F [sic-actually 105F]'- I suppose that's relatively safe since it doesn't store hot water, but I don't know if there's still a Legionella risk with the water that remains in there.
Storage HW heaters should be kept at 60C/140F to mitigate the risk of Legionella. From an environmental/kid safety point of view they say 50C but you can't win. I suppose the compormise is mixing valves to regulate the temp."

I think Alan has mentioned this before as an argument for not setting the tankless so low. My counter argument is that my hot water system, even if I had the tankless set much higher, is constantly going through heating/cooling cycles that don't have the water hot enough to prevent Legionella. If not the tank itself, the piping heats and cools between uses of the hot water. In the summer here in GA, it's probably 80F+ just sitting there.

The key thing that I'd argue makes my water safe despite the temperature swings is that I'm not removing the residual disinfectant (chlorine) before it goes through the temperature cycles.

The most recent Legionella death I know about was linked to a hotel in Miami (hot!) where the water was filtered (no disinfectant downstream) before distributing all over the property. That's when you have a much higher chance of problems.

Here is a link that might be useful: Miami Legionella article


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RE: Is anyone out there happy with their tankless water heater?

I have two Bosch units. Both 80 amp. For the kitchen, the 80 amp is fine - no problems. For the bath, 80 amp does not warm the water enough when the outside temperature is cold. We are on a well in Florida. Sadly, I have to get another one, likely 100 amp or 120. It is not the fault of the unit, mostly my fault for not getting a large enough one.


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RE: Is anyone out there happy with their tankless water heater?

dadoes.....good points, and that's encouraging to know that you didn't have a problem with running out of hot water. Thanks!

As far as Legionella is concerned.....I had never heard of that concern. But I don't think it will be a problem for us. We'll be able to leave our water temp. turned up high, because we're going to put on our shower faucets a stop for the water temp. I don't know what you call those things, but it will allow us to set our control so that the water temperature will always stop at the temp. that is comfortable for us.....never getting too hot.

And I don't mind if the water is hot for washing dishes (by hand or dishwasher). In fact, it would be better to have it hot. And I usually wash my clothes in cold anyway. So I think we'll be okay.

Thanks, folks!


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RE: Is anyone out there happy with their tankless water heater?

I'm on untreated well water, and have not had any known incidents of contamination or foulness/odor in the water in 6 years of living in this house with the tankless unit. I do occasionally raise the temp higher for specific tasks, such as washing a load of whites last night at 122°F (sometimes higher than that, 135°F or 140°F). Not uncommon for a week or more to elapse between "high-temp" tasks.

fiddleddd, be aware that tankless units require a minimum flow rate to activate and stay on. This helps guard against the unit activating, for example, in response to a dripping faucet. Setting the unit for a high temp and then involving a thermostatic shower valve can result in the valve throttling the hot flow down low enough that the tankless shuts off. A somewhat common complaint is that the shower runs cold, the hot flow is cranked up to compensate, it gets hot again, throttles back, runs cold again, repeat. Tankless intuitively works better if the temperature setpoint is not too high, ideally at the desired temp for the task at hand. With mine set at 104°F, I run only the hot water tap for showering. The flow rate through the unit stays plenty high enough that it doesn't shut off (I've never had a shower run cold) ... the tankless itself throttles back on how much heat it applies to the water.


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RE: Is anyone out there happy with their tankless water heater?

fiddled

I have a dual Rinnai tankless setup and love it. The shorter pipe runs and strategic placement of the units in the basement is key. I have read many posts of people unhappy with tankless due to the long time to get hot water but this was due to very long pipe runs and not the tankless unit itself.

My tankless units are right under the master suite - hot water in seconds.

The min flow rate mentioned by dadoes is something to watch. There can be issues with the anti-scalding shower valves and tankless units - a lot depends on the valve adjustment and resultant flow rate. If the hot water flow isn't high enough to kick on the Rinnai, you won't get hot water OR it will kick on and off intermitantly. It also isn't cost efficient to over cook the hot water and then cool it down at the tap by using a lot of cold water in the mix.

If you can, try to find a setting on the Rinnai controller so that you can run with the hot water on full (we run showers at about 90% on the hot side). We found that we had to mix in small abount of cold water in but that is because my Rinnai controller only allows tempertaure adjustments in 5 degree increments. If they allowed 1 degree settings, i could run the shower with no cold water in the mixture.

if you are planning to feed a bypass humidifier with warm/hot water, the Rinnai won't work due to the low flow rate on the humidifier water line. Use a small tank unit for those applications if needed.

You will also want to train yourself (and your guests) on how to use the facets with a tankless. If you are accustomed to turning the hot water on and off a lot, you will be short cycling the unit which isn't good for efficiency. With tankless it is better to turn the hot water on and let it run where possible and practical. A good example is washing pots and pans - better to fill up the sink with hot water, clean, then rinse all rather than start and stop with each item for cleaning and then rinsing.

You also did not mention if you were going gas or electric - I assuming gas which is better IMO. If you have a backup generator, put the outlets that you will be plugging the Rinnai's into on the backup so you can have hot water if the power goes out. The controller only needs a little bit of power to run the fan and ingnite the burners. If you are thinking about electric tankless and want backup when power is out , reconsider gas if that is an option because the amperage requirements on the elctric tankless units is very high and will drive you to need a very big generator. I live in an area where i gets very cold in the winter and we lose power often. It is awesome to come in from a full day of snowblowing and have hot water no matter what.


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RE: Is anyone out there happy with their tankless water heater?

I have a Rinnai, it's in the garage because the plumber detected that it was the closest to the main uses (it's on the opposite side of the kitchen and just under the master bath.

I've not had any problem with it. I do have a generator so the Rinnai keeps humming along on the propane even when the mains are off. I notice no real difference in the house with the Rinnai than my other house with a 75 gallon tanked unit.

I did by the remote control for the Rinnai so I could play with the temperature, but frankly, I don't really bother much. I leave it at 120 or so. I think the remote's in the vanity drawer, I've not seen it in a while.

I've got a well, no detected problems with the heater (I do have a softener).


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Retiree needs help with Rinnai R-85 and water lines

My husband and I are retiring, and we have purchased a 1900 square foot home that has a Rinnai R-85 tankless heater powered by natural gas. We are rehabbing the bathrooms, because after removing the floor and wall tile in both bathrooms we discovered rotten floor joists. The crawl space of the house had sprayed foam insulation, so the rotten floor joists were not discovered until we gutted the bathrooms. We jacked up the walls and replaced the floor joists, and we have temporarily screwed down the subfloor, so we can remove it to work on the water and drain lines. The hall bath will have one lavatory sink with faucet, a small bath tub with tub filler, a fixed shower head, and a hand shower for bathing grandchildren, washing the dog, and rinsing the tub after cleaning. The master bathroom will have two lavatory sinks and two faucets, a shower only with a ceiling mounted 8 inch rain shower head and a hand shower on a slider bar. Should the supply water lines be 3/4 inch as advised in many of the threads? We will appreciate any advice, because we have no experience with a tankless water heater. I hope to hear from all of you!


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RE: Is anyone out there happy with their tankless water heater?

I had a tankless water heater when I was serving in Korea. Loved it the two years that I was there & have been waiting for the states to catch up & start selling them at a better price.
I dislike the current cost of initial installation but very much love the functionality of them.


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RE: Is anyone out there happy with their tankless water heater?

Thanks for this (old) thread. I'm currently looking at tankless water heaters (gas) so this was wonderful
Thanks!


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RE: Is anyone out there happy with their tankless water heater?

3 years later, and my Myson is now 17 years old. And still going strong!

For anyone considering tankless, the most important calculation is your winter incoming water temperature. That will determine how many BTU's you will need to achieve the hot water that you need. And don't get hung up on using 3-4 fixtures at once. Realistically, that doesn't happen much. And the third person can just hold their horses for a bit if it does happen regularly.


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Tankless (Instant) gas hot water heater: Happiness personified

Hi,

We've had everything from wood, to gas to electric.

We've had tanks and tankless (instant) hot water heaters.

However now for the last 35'ish years we've had instant gas hot water... and it's been GREAT!!!

You NEVER run out of hot water. No one ever has to get yelled at for hogging all the hot water. You can run them all day long and the units don’t seem to care.

They normally last 20-25 years (a few of my neighbours still have their original units after 40 years)... and they're awfully cheap even with installation.

We've only on our second one. It's a Bosch TF 325 13P. This is a water heater not requiring power to turn on.

This one is now about 15 years old. The only problem we ever have is that the pilot light gets blown out a few times a year. If you get the hydropower version then the water power lights the pilot light each time you turn it on. This saves up to 25% of the gas (presumably on a system that is barely used?).

Our old unit was internal.. this one is external.

Even if you love having long showers you won't notice any increase in your gas bill. The unit uses heaps less gas than the gas room heater. It's only on when required and this ends up resulting in very modest bills.

There are virtually no moving parts in these systems so very little to go wrong.

Tank based systems always leak after 10 or 15 years... sometimes sooner. They also run out of hot water much too quickly. They also seem to use a lot more gas! When they do leak you've got a whole heap of mess to clean up.

Instant gas hot water systems rarely leak when they die. Our last unit simply sooted up and despite cleaning it and having the service agent out a few times they weren't able to get it to work properly. Still not quite sure what went wrong... as soot should not magically accumulate and the heat exchangers weren't leaking. The flue did not appear blocked... but perhaps it was? Or perhaps some other part failed and it started running too rich?

The 13P has only a 3.9 star efficiency rating as compared to 5 or 6 stars for some of the more efficient units. However the more efficient units require power and won't work if the power is out. No power and no hot water is not fun. However in practice I suspect that the efficiency rating is good for only about $10/yr of savings or less? It's the room heater that eats $$$ not the hot water heater. Likewise if your more efficient hot water heater breaks down your savings will evaporate in service fees. I suspect that the electronic versions may be even more prone to playing up... but only towards the end of their life or if you get unlucky. My friend has one and he's really impressed. He had a tank before this and when it leaked it flooded his roof space. That's not good for the house.

The 13P is only 13L/min but that seems sufficient. The only problem you ever have is if someone is trying to use the hot water on another tap. This is only a problem in the shower as the water volume changes and suddenly you have too little hot water. This isn't a problem for other uses as it just means it takes a bit longer to fill the tub. If you get a larger unit presumably this won't happen? However most users at our place know that low hot water pressure and a yell means someone is having a shower. Doesn't happen much otherwise it might be an issue. Maybe next time we'll upsize the unit to 16L/min?

While the hydropower option (water starts the pilot each time you use it) is tempting I've heard both good and bad stories about them. One caravan park I was at loved them as they were so trouble free. However I've read the occasional horror story where the igniter didn't work reliably and kept failing. Piezo electric igniters NEVER fail (they seem unbelievably robust)... but hydraulically ignited units might? So stick with the basic unit?

None of the instant gas hot water brands seem particularly troublesome. I picked Bosch because the service was exceptionally good on the last unit, parts seem easy to get, service cost was modest, installation costs were modest, there are lots of them in service and the service guys seem to know all about them.

It has always been surprising that so many people have tanks with their attendant costs and problems when the alternative is so cheap and trouble free.

Maybe few happy users bother posting because they're off doing other things (not worrying about hot water)... but I know a lot of users... and almost exclusively nobody ever has a problem (only once every 25 years). Out of sight out of mind?

Don't hesitate... do your research, pick a good brand, preferably without too many bells and whistles... and rush out an buy an instantaneous gas hot water system.

You probably won't have to mess with it for another 25 years... and that's just as it should be.

A VERY satisfied customer.

:-)
PS The area where I live was all originally outfitted with these units... so there are tons in service here.


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RE: Is anyone out there happy with their tankless water heater?

We've had a tankless in our home for about 3-4 years now. Wonderful endless HW but the delay to get HW has been very annoying.

Our next home we're getting ready to build I think we're going back to a normal tank. the lag time and constantly running faucets to get HW just aren't worth it.


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RE: Is anyone out there happy with their tankless water heater?

"Wonderful endless HW but the delay to get HW has been very annoying. "

Gosh. Completely lacking common sense is one thing, but expecting everyone else to lack it, too, is pretty brazen.

The amount of time it takes to get hot water has NOTHING to do with whether the heating is tankless or not. It ONLY has to do with how far away the heater is. (and whether or not there is a recirculation system) Since a tankless only needs to be installed on a wall, and doesn't take up floor space, it's often easier to put it near the point-of-use. That means it will take LESS time to supply hot water. Of course, that doesn't mean installers actually have the sense to put them near the point-of-use. Sorry, apparently your installer didn't know what he was doing.

Me, two of my family members, and a couple other homeowners I know all have tankless water heaters, and are all generally happy with them.


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RE: Is anyone out there happy with their tankless water heater?

pprior, as you are planning to build another home you have an opportunity to "do it right" on the design of the system. Simply slapping it where an old tank was is simply perpetuating the mistakes of the original low cost bidder.
I re-modeled lat year and did a total re-pipe. I was able to position my Rinnai so my longest run to a hot water faucet is 18'.

As well, I analyzed the piping lay-out for required flow rate at the faucet and did not oversize my hot water pipes. If you look at 1/2, 3/4 and 1" pipe they have cross sectional diameters of .19, .44 &.77" respectively. That equates to volume of water and that equals delay. Your problem could easily be caused by the existing pipe lay-out.


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RE: Is anyone out there happy with their tankless water heater?

davidrt28: I am a tankless owner, and happy with my choice. However, what you said about there being no difference isn't accurate. A tank water heater will have hot water in about the first 6 feet of pipe. A tankless will have to purge and then fire in order to heat the water. In total it adds about 3 seconds of wait time.

Much of the lag in hot water is really attributable to poor design (over-sized pipes and excessively long runs) and lack of insulation on water lines - but a tankless will introduce about 3 seconds of delay because it's tankless.


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RE: Is anyone out there happy with their tankless water heater?

The delay to hot water with a tankless is also affected by the incoming water temperature. That directly affects user experience. With a tank, the user does not typically realize how long it took the water in the tank to get hot.

I had a Rennai tankless installed several years ago. Great unit, no complaints, but it is tankless - and the longer delays to hot water on the coldest winter days can be a bit annoying.


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RE: Is anyone out there happy with their tankless water heater?

Please be aware that only folks that have problems post about products on the internet. I have had a Bosch Aquastar 125b for almost 10 years. Very happy with it. Have saved 20% on my gas bill all that time, so that would be about $30 to $40 each year. For me, it is more about my carbon footprint, but having installed it myself, changing out a tanked WH, It has near paid for unit, which cost almost $500. I don't have hard water problems, so I have only flushed it once, about 4 years ago. Nowdays there are a lot more choices. I am considering my next one to be an electric, powered by photo voltaics, in essence, a solar water heater with less maintenance, and space requirements.


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RE: Is anyone out there happy with their tankless water heater?

camp9: I'm sorry, but I don't believe that's correct unless your tankless was seriously undersized.

Virtually every tankless heater I've seen has a variable BTU input. When the water inlet temps are lower, the heater increases the amount of fuel to compensate all the way up to its maximum BTU input.

Once a heater reaches its maximum BTU input, it will throttle water output if need be to maintain a constant temperature output.

If your heater was significantly undersized, it would have been restricting the GPM output on the coldest days enough to increase wait times. That's a design issue, not a water heater issue.

A properly designed system should only introduce 2-3 seconds of additional wait time for hot water unless a circulating system or small storage tank is used in order to reduce wait times more.

Insulated water lines will reduce the wait times between uses by not allowing the pipes to cool.


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RE: Is anyone out there happy with their tankless water heater?

Besides ignition you can add the additional pressure drop a tankless has over the tank. This reduces the flow rate to a wide open fixture, thus adding to the wait time.


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RE: Is anyone out there happy with their tankless water heater?

My tankless installation is now going on 18 years. With no problems. I have none of the "extra" waiting time that myth would have exist. No pressure drop either.

How long you wait for hot water to reach a fixture is an element of the overall design of the plumbing runs, and how much cold has to be purged from those runs. It's not a result of the production method of that hot water. If the heaters are in the identical locations, then the identical amount of cold water has to be purged from the lines before hot water reaches a fixture.


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RE: Is anyone out there happy with their tankless water heater?

zl700, that's really grasping...

Virtually all faucets are limited in their flow rates. The pressure drop introduced by a tankless would not be a factor.

As I mentioned a tank heater will keep hot water in the first 6 feet or so of pipe. So that, in addition to the time it takes a tankless to fire, adds 2-3 seconds to a wait over a tank heater.

That's only if the pipes have cooled. My hot water lines are insulated, so I don't have that wait every use - just when there's been an amount of time between uses.


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RE: Is anyone out there happy with their tankless water heater?

Davidrt28. My aren't you quite the smart ass... I am not lacking in common sense, I spent several thousand dollars installing a tankless unit, was very excited to get it and in fact replaced a perfectly functional unit to get it.

The simple FACT is that our times to get hot water are very noticeably longer Han with our prior tanked unit. Especially noticeable in the kitchen were it takes probably at least a minute of full open tap. You can post what you want in whatever rude way you wish but I built this house, I've lived in it for over 10 years now about 3-4 with the tankless unit.

Others have suggested that our home was not set up correctly (we do have a large 3 story home about 5500 sq ft) and my personal belief is that due to the pipe insulation we installed we had enough convection in the system with the tanked unit that was kept warm that the hot pipes always had some warm water present. Of course that wasted energy.

I never said that water leaving the unit took longer but there is NO DOUBT it takes longer to the tap. I'm not bashing tankless units but potential users need to be aware of the real world use. My plumber said most people who installed them ended up going back to tanked units. I thought he was just behind the times but now after living with one for 4 years and getting ready to build another new home we will be going back to a (super insulated) gas tanked unit.


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RE: Is anyone out there happy with their tankless water heater?

pprioroh:

We tend to have large, spread out homes and it's not uncommon design for the water heater to be placed at one end of the house and the master bath, for example, at the other.

None of that is particularly good design, but I get it that in a retrofit situation you can't change some of that.

Often times with tankless it's possible to move the heater closer to the point of use - this is especially true with a condensing unit where the vent is cheap PVC.

Despite the marketing to the contrary, the efficiency of tankless doesn't come from the fact that there isn't hot water cooling in the tank, it comes from the dramatically lowered flue temps. A standard gas tank water heater with an atmospheric vent - no matter how well insulated -- can't come close.

There are tankless / tank water heaters out there that combine a tank with a tankless heater. This gives you most of the operating efficiency, less delay, no cold water sandwich, ultra fast recovery (almost continuous), and a smaller BTU/h input so it can be done without as many concerns about gas supply.

The link below is an example: I have no experience with this unit, just using it as an example. It's 100k BTU/h input at 96% efficiency. A standard tank is ~40k BTU/h at 62%
A tankless heater is ~200k BTU/h (which is why there can be concerns about gas supply).

Take a look at these types of heaters for your next house.

Here is a link that might be useful: Hybrid gas water heater


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RE: Is anyone out there happy with their tankless water heater?

Jake- that looks like a great product! Will definitely consider. We also will likely be PEX in next house with home runs vs. larger trunk lines of copper which will likely help with distribution times. thanks again, those are the kind of comments that are actually helpful on this site!


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