Expansion tank

[weiland13]

Are well pump expansion tanks acceptable to use as a pressurized system's expansion tank?

 

[ewdudley]

Depends who you ask. I say well pump tanks are built to a higher standard of corrosion resistance, so if you come across one for cheap, go for it. Except you should add add enough PEX, copper line, or baseboard finned tube to get the temperature down to what the tank is spec'ed for. If buying new, the purpose built hydronic tanks are good enough.

 

[mr.fixit]

That's what I used. It's about 10'-12' off of the main plumbing via 1/2" pex.
It barely gets warm.

 

[stee6043]

I'd say the real risk with well tanks is if you do have a failure and there is damage to your house a well informed insurance adjuster could deny a claim based on the incorrect type of tank being used. Same goes for passing inspection (if you plan to pull a permit). Otherwise, I used the proper tanks and I can confirm that I've never had them get anything other than warm.