Thumping sound

RuffinoVino

I recently started to hear a thumping noise that happens during and for about 15-20 mins after the boiler stops running. The nose is only occuring on the far run side of the boier and it's happening in the floor or wall. It also doesn't happen every run or each time the run stops but probably more than 50% of the time. It's not your typical pipe or radiator bang but a deeper thump sound. It's a thump that is continuous for about 15-20 mins that occurs every few seconds. It's not a one thump that happens one time it's continuous. The only thing I've done recently and not even sure if  it started around the same time but I did make some radiator air vent changes. I did put the original ones back and it still persists. Any thoughts on this sound?

ethicalpaul

My main pipe does this sometimes after the end of a call for heat (like 30 minutes later). A single thump. I'm sure it's the pipe noisily sliding past some beam or hanger. I wouldn't expect changing your venting to affect it if it's the same sound I'm hearing.

Intplm.

The pipes changing temp will do this from time to time.
Also, check for proper pipe pitch back towards the boiler allowing for condensate to drain back to the boiler.