The noise usually happened when the heating first turned on — a fast series of clicks — then again when the radiator cooled down. That pattern is the giveaway.
1. Pipes Expanding Against Brackets
In my place, the pipes running to the radiator were slightly tight in the floor clips. When they expanded, they clicked. Loosening the clips and adding a tiny bit of padding stopped the noise instantly.
2. TRVs Can Click When Opening or Closing
I had a TRV that made a small tapping noise every time it adjusted. Removing the head and refitting it usually settles this.
3. Air Moving Through the Radiator
Clicking also happens when air pockets move inside. After bleeding the radiator properly, the noise reduced massively.
If your radiator is cold at the top as well as clicking, check this:
Radiator Warm at Bottom but Cold at Top
4. What Finally Stopped the Noise
Padding the pipes and bleeding the radiator fixed about 90% of the issue. The system sounds “normal” now — no late-night tapping.
More heating fixes here:
How to Keep a UK Home Warm for Cheap (Complete Guide)
