It's coming from our underfloor heating circuit, probably in the ceiling void between the ground and first floors, and is amplified by the pipes passing through a cavity wall into our garage (where they then drop down to the UFH pump and manifold near ground floor level).
It's a rapid rattling sound, lasting about a second, repeated every 20-60 seconds, that starts when the UFH comes on and then dies out over the next 10-20 minutes.
The noise is intermittent and began after 11 years of the system running without any issues. The boiler is a Greenstar HE Plus combi working at 2 bar and regularly serviced. The central heating zone is fine.
Here's a recording (made through the window):
Any ideas what the root cause is?
Thanks!
BTW I can't easily access the place where the pipes pass through the wall, so I want to stop this problem at source rather than by packing/clamping the pipes.
It's a rapid rattling sound, lasting about a second, repeated every 20-60 seconds, that starts when the UFH comes on and then dies out over the next 10-20 minutes.
The noise is intermittent and began after 11 years of the system running without any issues. The boiler is a Greenstar HE Plus combi working at 2 bar and regularly serviced. The central heating zone is fine.
Here's a recording (made through the window):
Any ideas what the root cause is?
Thanks!
BTW I can't easily access the place where the pipes pass through the wall, so I want to stop this problem at source rather than by packing/clamping the pipes.