[eye144]

I have a gas fired house heater water circulating making bump sound occasionally. We have never heard it before this few days. When I heard it, I went and listened and it was not during firing, but possibly right after or at shutoff, because everything was very warm. Should I be concerned? Any preventative maintenance to do? Thank

[eye144]

It happened again, after the heat cycle. I thought it came from the ceiling where the heat vent or else pipes were contracting after the cycle.

[hvac1000]

Actually every heating system especially boilers should be checked every year. The noise you here could be coming from the pump on shut down or a bit of air might be in the system. Noises are almost impossible to detect here but are better checked in person by a visit from your local HVAC person. A slight noise lie that is probably nothing to worry about BUT it might be smart to get it checked.