tankless water heater

Old 03-10-16, 06:33 PM
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tankless water heater

Trying to install a tankless water heater that requires 3 x 40 AMP Double Pole Breakers, is this possible with my current setup?

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Old 03-10-16, 06:42 PM
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Welcome to the forums.

Short answer - nope. Long answer would be a question back to you of where do you see those three breakers going? You're not showing us any open spaces.

What level of service do you have? I'm not sure 200 amp service would suffice for that kind of draw.
Old 03-10-16, 06:45 PM
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Also just a question...

Do you have the tankless heater already?
Why do you want or need a tankless heater?
Old 03-10-16, 06:47 PM
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Best would be to run a new 150 amp subpanel to the vicinity of the TWH then put your 40s in that. However you probably need at least a 300 amp service which is not common for residential.
Old 03-10-16, 06:59 PM
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You are going to need to recoup the cost of a service upgrade before you ever start saving any money. The service upgrade might be several thousand dollars.
Old 03-10-16, 07:20 PM
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So a TWH that requires 2 40 would be better?
Old 03-10-16, 07:35 PM
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It can be done as others said. It usually works fine with 200A service.
However, I would not recommend electric tankless water heater unless you live in southern states. They often have hard time keeping water hot during winter season when inlet water temperature is very cold.

I'm in northern Virginia and installed Ecosmart ECO 27 (27kW) at job once. It requires 3 40A breakers just like your water heater. It was installed in a highrise condo unit and cold water comes through ceiling of parking garage. Water temperature was around 40F. Outlet temperature was only about 75F. Many single handle shower valve won't allow you do have full hot even with limiter set to maximum and his was one of those. So even colder water at the shower.
Powere in that condo being 208V did not help either. It works as 23.4kW at that voltage.

It was installed to replace 24kW, 2 element tankless that was there before. Which was producing even colder water. Customer had enlarged kitchen by removing water heater closet and replacing it with tankless a year before. He wasn't aware of the problem until winter came.
Old 03-11-16, 02:53 AM
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I'll agree with the others in that an electric TWH is not going to be economically feasible due to the start up costs and running costs. Gas would be much more beneficial. I have never installed one, but have removed a few on remodels where the customer's first request was to "get rid of that hog".

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