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Water heater(s) for 140+ ft wide house?

Posted by BAVE (My Page) on
Wed, Feb 22, 12 at 18:33

Hello. We're currently in the process of planning a custom build in Texas. The home estimate included one 50 gallon water heater but our concerns are the size of house (141 ft wide split bedroom design 5000 sq ft living), number of baths (5 bathrooms) and space. The electric water heater is planned in the garage but we are considering adding a second on the opposite side of the house for the master and another bathroom.

Should I consider tankless on the unit not in the garage or opt for a smaller tank in attic or other area?

I've read several negative articals on tankless but I am skeptical of their bias. What are your thoughts on tankless heaters?

Follow-Up Postings:

RE: Water heater(s) for 140+ ft wide house?

Tankless electric aren't generally worth the cost.

50 gallon electric is pretty small for your size house. My builder usually would do 2 50 gallon units with a recirc pump with a house your size. Alternatively, you can put the tanks at different points of the house.

Most people cringe at the idea of a hot water heater in the attic because of leaks.

If you only have electric (not NG), you should really consider an alternative to electric strips for heating hot water - it costs an average of $600 a year for electric and if you have 2 tanks or a loop, it will be more. Heat pump hot water heater is an option but it does make noise but it might be nice in the garage (would help keep it cool in the summer). Solar is another option but payback depends a lot on local incentives. Here, for straight electric, it is about 5 years. Even with just the federal credit, payback is about 10 years. Heat pump pays back in about 2 years if the noise is not an issue for you.

RE: Water heater(s) for 140+ ft wide house?

141 feet? What are you building? A mini storage unit?

Gas tankless has it's place, and that place is a new build when you can specify the larger than normal gas service from the beginning. Electric tankless is pretty iffy no matter what or when because of the huge electrical draws it will have. You'd need to plan for a 400 amp service minimum, and maybe even 600 amp.

Tankless is no panacea for siting the water needs with some good sense and an intelligently designed plumbing run.

RE: Water heater(s) for 140+ ft wide house?

Slightly off topic, but I would like to see your plans. We are planning to build a 5000 sq ft one story home with split bedrooms as well. Ours is only around 100 ft wide - more like an H layout. We are still working with our architect and would like to see your plan out of curiosity to see what ideas we may be able to use in ours. I will send you a private message, so you can respond that way if you wish. Thanks!

RE: Water heater(s) for 140+ ft wide house?

Thanks for the replys. Turns out the contract states 2 50 gallon heaters (located in garage) but we have the option of dual NG tankless for $2500 more.

Momto3kiddos: we opted for a very wide build because we have a shallow acre cul-de-sac lot. Here's the elevation.

Here is a link that might be useful: ELEVATION DRAWING

RE: Water heater(s) for 140+ ft wide house?


my house is over 100 feet wide and I ran into this exact issue. When I did the calculations of how much water is in a 100 foor long run (with the pipe sizes I had) it was over 5 gallons of water. Look at the gallon per minute ratings on the faucets and you can calculate how long it will take hot water to get to the sink (a long time).

I used gas tankless but it really doesn't matter what the hot water plant is. What does matter is how close (in pipe run) that hot water source is to the sink that or tub it is feeding.

If your houses is like mine where you have master suite on one end of the house and kitchen sinks on the other end, you might think about putting one hot water source near each end. I thought about a compromise (the middle of the house - in the basement) but then everyone suffers. I ended up with tankless under the master suite (our house - we get hot water first) and use a recirculating system for the kitchen. One day I will add a hot water tankless on the other end so I can remove the recirculating system. I have a basement which makes this much easier. If you do end up going with something in the attic (not recommended), make sure you have a pan and drain beneath the hot water plant in case there is a leak and put a water alarm on it which will sound off if there is a leak.

A good buddy of mine built his house in Florida where there are no basements (similar to texas I understand). He put his hot water tanks in the garage - and they were a long way from his tub. On top of that, the water pipes ran underground where the hot water would cool off before it reached his tub. He absoutely hated it because he has to run his tank at a very high temperature do get decent hot water temp at the tub faucet. And there is not much he could do about it. I helped him design a hot water recirculation system which helps get hot water to the tub faster but he pays for it in the monthly gas bill.

Plan carefully.

RE: Water heater(s) for 140+ ft wide house?

Sniffdog, thanks for the reply. Looks like we're going to opt to have one NG WH in the garage (near bedrooms, etc) and a tankless NG WH in the attic above the master bath (master bath and one additional bathroom. We have a split plan so the master bath will be approx 100 ft from the garage.

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