Water heater expansion tank

[Gagecalman]

Already asked but do you have a well or public water?

 

[Hwkmn05]

Spring

 

[Sponsor]

 

[Jeff H Young]

a check valve on a hot water return line shouldn't create a closed system .

Yes there has always been a larger expansion tank. WH was installed and that plumber installed a small one above it. New plumber said it was not needed at WH because I had one on water line already.

That makes a difference depending on where your check valve was installed if a check valve was downstream of the big expansion tank then the small one would still be needed. If this guy is a great plumber he probably can solve this easily .
Is the problem already fixed ? where are you currently with it?

 

[Hwkmn05]

Check valve is at the pressure tank. There are no other valves between that and the WH. No expansion tank needed and the difference is minimal.

 

[Jeff H Young]

Check valve is at the pressure tank. There are no other valves between that and the WH. No expansion tank needed and the difference is minimal.

Based on current info not having a tank at the water heater isnt causing your issue unless the tank was somehow grossly undersize. Dont know what" differance is minimal " would be refering to.
id say your main expansion tank needs testing

 

[Reach4]

Spring

Private?

 

[Hwkmn05]

Private?

Yes

 

[Hwkmn05]

Based on current info not having a tank at the water heater isnt causing your issue unless the tank was somehow grossly undersize. Dont know what" differance is minimal " would be refering to.
id say your main expansion tank needs testing

I was looking at that and wondering the same thing. With spring water content of iron and sediment, guessing tank is 20 plus years old could be impacted.