Expansion tank leak?

ALH_4

It sounds as if the diaphragm in your expansion tank has failed and I bet the relief valve drips. If so, I would replace both the expansion tank and the relief valve. The system will have to be drained for repair. Adding water to your system regularly introduces oxygen, which will cause premature failure of iron components in the system.

Jeff_107

Replace Expansion Tank?

Hi all

I have a Weil-Mclain hot water boiler system. My expansion tank is very hot on top and cold on the bottom. The PSI when running is about 18psi. When it is off is drops to about 4-6psi. I fill it with water every other day to reach the desired 12psi. I don't hear the water entering the system form the cold water supply. However - when i disconnected the cold water supply line to check for clogs it was running fine. Is it possible my "spring loaded check valve is stuck in the closed position? if so, do i need to change the whole unit?

Thank you

Jeff_107

Thanks Andrew -

Will do.