I have a gas boiler hot water baseboard heating system along with a gas hot water heater. The home is about 8 years old. Recently the TPR valve started leaking intermittently on the hot water heater ( not excessively hot water so I don't think its a thermostat problem). I have a water pressure regulator on the main line from the city supply ( just background). The pressure is good and I actually dropped it a little...I changed the TPR and it still leaks a little. I do have an expansion tank near the boiler and it sounds hollow and when I let a little air out of the refill air valve only air came out ( seems OK ?). Do I need another smaller sized expansion tank before the hot water heater? I'm out of ideas. Seems strange that I might need another expansion inline after 8 years? I have two heat zones w/circulating pumps and added another in the basement this summer, but that was just tee'd off the the other two? Any help would be appreciated!
Joe
Joe