Clicking in rads when central heating turns on

[mints73]

I had a new combe boiler fitted last year when my old boiler and header tank were removed.

The system was cleaned out etc. and the system has inhibiter in, now I think the clicking is the sudden increase in presure in the steel rads when the pump starts up.

It goes on for about 15 to 30 secs but it does not click in my heated towel radiator, I am not having to bleed rads so I dont think its air and in any case the noise is far sharper than that.

It also somtimes happens althought for only a second or so when the boiler fires for domestic water, and the central heating is not supplying heat.

I have heard the odd single click several hours after the system has been off.

Otherwise the system works fine is it just older rads.

 

[Stamina]

most likely just expansion noise on the rad brackets

 

[libby lou lou]

Mine click, expanding, also when cooling down, it can also be down to improperly secured piping, which sounds like it,s coming from the rads.

Even the pipes rubbing against wooden joists can cause it,This post isn't every answer, but should cover 90% of the reasons.