When replacing an electric hwt to a coiled tank, which is heated by a hot water boiler how do you resize the tank? I have a 40 gal electic, can I change to a smaller coiled tank. My boiler water will be 180.
Thanks, Phillip.

 

Does the 40 gallon unit work ok for you (outside of a leak?)
Why do you want to resize?
plumber john

 

Phillipaldner:

Any company that makes hot water heaters will help you size your hot water heaters (both tank and coil style).

If you have a house, I kinda doubt that any company is going to sell a small enough coil heater for you. I own an apartment block, and I'll be switching to a coil heater and storage tank when my existing tank style heater throws in the towel, and I'm barely able to meet the requirements of the smallest coil type heater A.O.Smith makes. They wanted to sell me another tank style heater instead.

In all honesty, for a house, you really don't need a coil type water heater unless you've got both money and space to throw away. A PROPERLY sized tank style heater should last you many years.

If I was in your boots, I would probably install two tank style heaters in parallel. The advantages to doing this are many; you can limp by on one heater while the other is being serviced or replaced, you have twice as much hot water available to you with no reduction in the recovery rate, you can turn down the thermostat on each heater and simply use more "less hot" water when having a shower so that each heater will last longer than a single heater would because the thermal shock will be lower with only half the cold water coming in. Gawd, but that was a long sentance!