After changing a leaky pressure relief valve on my furnace, I noticed that the diaphragm expantion tank in my hot water heating system was filled with water.
I shut off the supply and opened the pressure relief valve. I then pushed on the pin in the bicycle-tire valve on the expansion tank and let all the water drain out of it through the boiler and out the expansion tank.
So far so good.
I am not sure if the diaphragm failed or I need to recharge the expansion tank with air.
Can anyone tell me the procedure for recharging it?
Bill