Do I go tankless water heater or wait for 75-gal gas heater?

tabbaldwinJune 25, 2010

I'm X-posting in hopes of a quick response:

The builder just called and said that the 75-gal high output gas water heater is currently unavailable because the company is based in Nashville, and something about the floods have caused problems with getting it.

His solutions to me are a tankless 9.7 gal system or put in an electric heater until the gas heater becomes available again. The reason we wanted gas was in case of power outages, we'd have hot water.

Any suggestions/thoughts for me?


Thank you for reporting this comment. Undo

We got the 9.5 gpm tankless, actually 2 of them, for our house. My parents have tankless heaters in their house and love them!! That's all they have on their propane tank and they are going through about 1 tank per year.


    Bookmark   June 25, 2010 at 12:45PM
Thank you for reporting this comment. Undo

Thanks for the reply, Vonda. I hope it's a small propane tank that they're going through 1x / year ;-) For some reason, I had thought tankless was electric, but I've been learning differently. However, I'm also reading that well-water (which we'll have) isn't always kind to tankless, depending on water hardness, etc.

BTW, I'm originally from Arkansas. Hi!

    Bookmark   June 25, 2010 at 1:30PM
Thank you for reporting this comment. Undo

How about two water heaters? (We have two 50-gal. Unlikely both would quit at the same time.) If you want instant hot water, get a circulator. I LOVE not standing around waiting for the hot water to reach whatever sink I'm using.

    Bookmark   June 25, 2010 at 2:52PM
Thank you for reporting this comment. Undo

Wait or go to a diff supplier. Tankless electric requires a large capacity electric main box because when they go on the meter will shoot to the moon. As to two tankless propane units using a tank full of propane for a year. A pretty std tank size is 250 gallons, of which they only fill to 200 gallons....around here that'll run you about $400, which is absurd to heat household water. I have a propane 50 gal water heater with an extra insulating blanket that we spend about $600 to heat the house in the winter and yearround minimal clothes dryer and the water heater. In the summer (no furnace running) the usage is about $10 per month. Twelve months = $120. No tankless of ANY variety can touch that.

    Bookmark   June 26, 2010 at 6:19AM
Thank you for reporting this comment. Undo

Thanks for all the input. I think we've eliminated going the tankless route. I will talk to the builder about a different supplier--you'd think a plumber could get any brand and install it. Just seems weird to me, now that I think about it.

    Bookmark   June 26, 2010 at 11:07AM
Thank you for reporting this comment. Undo

Just checked in with the builder again. I misunderstood the problem. It's not the actual water heater availability that's the problem, it's the power vent that goes with it. And now I learn that with this type of venting, we'll still need electricity for the gas water heater to work. CRAP! That's the whole reason I wanted a gas water heater.

    Bookmark   June 26, 2010 at 11:59AM
Thank you for reporting this comment. Undo

If the HW heater is on an outside wall, perhaps you can use a direct vent heater instead.

The fan for the power vent doesn't take much power. You should have some kind of backup electricity anyways if outages are a regular occurrence in your area.

    Bookmark   June 26, 2010 at 6:42PM
Thank you for reporting this comment. Undo

Well, it is on an outside wall, but that's the part of the basement that's solid earth behind it.

I think we'll go with a temporary electric one until the one we want can be installed.

Thanks all.

    Bookmark   June 26, 2010 at 9:52PM
Thank you for reporting this comment. Undo

The vent can be extended to 8' with a horizontal discharge. If the power vent run was greater than that, then I guess electric is your only palatable option.

    Bookmark   June 27, 2010 at 2:44AM
Thank you for reporting this comment. Undo

We have two tankless Bosch on demand heaters. More hot water than we could ever need and I HATE them. It takes a while for them to power on and heat the water (10 sec) and then additional time to run from the source to the faucets. Hate them! If you want to wait more than 30 seconds for hot water every time you go to wash your hands, face, dishes, etc, just install a few on demands and they fix you right up! 97% efficient but who cares when it takes forever to get hot water.

Hate them!

    Bookmark   June 27, 2010 at 8:47PM
Thank you for reporting this comment. Undo

mdev - electric or gas? I am guessing since you quote 97% efficient that it is gas. Since it takes 10 secs to heat the water and you wait for more than 30 secs - sounds like you have 2 issues.

I have a recirc pump and instant or less than 5 secs is pretty nice. It is tricky to get that to work with an on demand heater and requires small buffer tanks at various points throughout the house (which probably isn't worth it)

    Bookmark   June 28, 2010 at 7:43AM
Thank you for reporting this comment. Undo

mdev- you'd have almost the same amount of time to get hot water with a tank unit in the same spot as your tankless. That's more a function of the piping than the heater itself. And I don't have personal experience with the Bosch, but I've read where folks weren't entirely happy with them over the years. I'd stick with Rinnai, Noritz, or Takagi if I was going tankless. And I say that with a shed-full of Bosch power tools.

Fine Homebuilding had an article a while back that's relevant to mdev's situation. They installed a small- 10 gal or so, electric heater closer to point of use and fed the output of the tankless to that. That cut the wait time and buffered for times when the tankless hadn't kicked on or had cut off b/c the flow stopped briefly.

tracey_b: Either your power vented gas heater or a gas tankless will not work with the power out. That's the price for higher efficiency, I guess.

    Bookmark   June 28, 2010 at 8:57AM
Thank you for reporting this comment. Undo

Got to say it! We have two Rinnai tankless heaters and I will not go back to tank heaters! As there is a heater on the exterior of each side of the house, close to bathrooms, laundry and kitchen we do not have to wait for hot water. Limitless hot water on demand - just as it should be! LOVE them!

    Bookmark   June 28, 2010 at 11:10AM
Thank you for reporting this comment. Undo

I've heard that tankless often don't do well on well water (minerals)???

Gee, I thought all our decisions were over!

    Bookmark   June 28, 2010 at 11:42AM
Thank you for reporting this comment. Undo

I initially was going with tankless but decided to go with tanks in the end. I have two tanks(natural gas) on each side of my house so I hope I don't have to wait long for hot water. I'm also heating the water with geothermal so energy cost for me should be minimal anyway.

There is a lot of info on the Terry Love forums and that is where I got the info before making my decision. Here is one thread with a bit of info but for an informed decision you should read a bit on the TL forum. Good luck.

    Bookmark   June 28, 2010 at 11:47AM
Thank you for reporting this comment. Undo

The reason we have 2 tankless heaters is so both of them are close to the point of use, which equals less wait time. I also drew our house plans to make sure my hot water use areas were "clustered" because of this. Due to the piping in our double wide, we have to wait up to 5 minutes for hot water from a tank heater. Ridiculous. I have played around with my parents' stuff and have never waited more than 10 or 12 seconds for hot water because their heaters are also near the point of use. Their and our tankless heaters are Rinnai, btw. The only instant hot water I have ever experienced was in a really nice hotel... ;-)

I don't know how big our current tank is, but we often run out of hot water for our family of 4. I'm looking forward to never dealing with that again!!

Hello to a fellow Arkansan. Might not be the greatest state in the Union, but it's home. :-)

    Bookmark   June 28, 2010 at 12:59PM
Thank you for reporting this comment. Undo

It's wonderful to have 'instant' hot water all over the house. It's cheap to buy and run a recirculating pump. (It IS like being in a hotel! LOL)

At first I was unhappy I hadn't thought to consider tankless when we built 10 years ago, but after talking to our plumber and to people who have them, I'm less unhappy. I know that's not 'green' thinking, but it's expensive to install the heavy duty electrical for tankless; the heaters themselves are expensive; people don't like waiting for the water to heat.

    Bookmark   June 28, 2010 at 5:20PM
Thank you for reporting this comment. Undo

If your on well water, your well pump's not going to work when the electricity is out anyway.

    Bookmark   June 28, 2010 at 5:40PM
Thank you for reporting this comment. Undo

I designed my house with a central propane 50 gal water heater. Virtually everything is sink about 5 ft, powder sink about 3 ft, master bath about 6ft, upstair baths are 8 ft and 15 ft.
No waiting long. Low water waste and low wasted propane.

    Bookmark   June 29, 2010 at 5:27AM
Thank you for reporting this comment. Undo

If you go tankless, let me suggest not getting the Rheem branded Paloma units. I have two (in parallel), one broke about 1 month into service (full replacement after two failed attempts to replace the PCB), and now another is not working properly.

    Bookmark   June 29, 2010 at 9:02AM
Thank you for reporting this comment. Undo

I'd be a little concerned going tankless on well water. Just because of potential for scaling issues, assuming the water is hard. You'd need to get the valve kit that lets you recirculate cleaner (i.e. vinegar) through the heater. And then you'll need to have someone do it, or DIY (sump pump, tubing, bucket o' vinegar). Not sure how often- might be 1x per year, might be more.

    Bookmark   June 29, 2010 at 11:51AM
Thank you for reporting this comment. Undo

Well, we live in Nashville, and I can confirm that the A.O. Smith factory was under at least 8 feet or water and was out of commission.

We have two tankless (gas) Takagi brand and are very happy with that choice more than 3 years after building. We were flooded in our basement (2 feet) and the heaters need to be replaced, but the tankless water heaters are fine.

In our previous house we had a decent efficiency gas water heater and no other gas appliances. For a much bigger home, with gas (plumbed) grill outside and gas rangetop, I still pay less for gas in non-heat months than at the 1/2 size condo, so the water heaters are definitely efficient.

Good luck with your choice.

    Bookmark   July 3, 2010 at 8:11AM
Sign Up to comment
More Discussions
Master Bath revisions
Which revision do you like better? There can only be...
Floorplan review please
I would love to get feedback on this floor plan. The...
What is a decent size for a breakfast nook?
I am looking at my house plans and I think the breakfast...
Opinions for master bath and closet doors
We are building a Shook Hill and have been stalled...
Dark hardwood vs lighter hardwood floors
I'm trying to decide which type of floors we should...
People viewed this after searching for:
© 2015 Houzz Inc. Houzz® The new way to design your home™