Kettling, banging, or a knocking pipe
A boiler that's gone quiet for years and suddenly starts making noise is telling you something changed inside it. Kettling, that rumbling or popping sound, usually means sediment has built up on the heat exchanger and water is boiling in pockets around it. Banging or knocking as the system heats up can mean a pump is wearing out or air has gotten into the lines. None of these fix themselves, and the longer the heat exchanger runs that way, the more it costs it.





