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 Expansion tank
Author: yonson (SC)

I have a mid 70s two-story home. Copper pipes. A 50 gallon electric water heater. On the cold side of this water heater is a 2 gallon bladder expansion tank. I have no boiler and no hydronic in the house. What should I pressurize the expansion tank to?

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 Re: Expansion tank
Author: steve (CA)

The tank pressure should match the static incoming water pressure.

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 Re: Expansion tank
Author: davidimcintosh (Canada)

Do you have a well and a pump then? I believe "An empty well pressure tank's pressure should be at 2 psi below the cut-on point of the tank. The pressure switch will activate the well pump when pressure drops below the cut-on point."

If you are on a municipal system (no well or pump), I am not sure why you would even have a pressure tank? Poor municipal pressure? Odd.

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 Re: Expansion tank
Author: bernabeu (SC)

some muni systems are CLOSED with checks at the meter

the expansion tank is for thermal expansion by the water heater which can not 'relieve' into the main


"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

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 Re: Expansion tank
Author: davidimcintosh (Canada)

Ahhhh, ok, interesting, that makes perfect sense.

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