Clicking Radiator

We have a very loud 'ticking' noise from one radiator in our house that comes and goes every 4 or 5 minutes. We have normal "on / off" valves (as opposed to thermostatic valves). What could cause this? It is an upstairs radiator and is one of 5 in the house, one of which is not connected at the moment due to decorating. The water pressure in the system is a little higher than it should be at times, but with the noisy radiator turned off the pressure is normal and there is the other radiator to connect back up.

Expansion & contraction of the rad when the water is heating cooling

Any way to cure this?

see if those little "u" shaped plastic errr thingys are on the rad bracket. if not bang something between bracket and rad. ie some cardboard, plastic ptfe...whatever.

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selmanj said:

Any way to cure this?

Click to expand...

I cant sort mine out all I manage to do is move it to another area.
The plus point is I do my heating is on without feeling the rads in the morning.

The noise is not just when the heating comes on / goes off. Every few minutes (last timed at 8 and 3 minute intervals - when the pressure is at its uppermost and lowermost in its cycle) the one radiator loudly "clicks" (noise similar to the pipework warming up / expanding). I read recently (a link on this site somewhere) about "balancing radiators". I can see why this might be done and can also see this might be a cause of the noise, but the link does not explain what happens if a rad isn't balanced?? If the water is entering and leaving the radiator at the wrong temperatures (either too hot in or too cold out) then the expand and contract of the radiator would be regular and intermittent and could cause the noise...is this a sound theory?? (I have fitted new valves to all the rads when we moved in last year. All instructions i have seen though do not really talk about balancing...it seems to be a divine right of the locksheild valve that will magically happen!) How would i go about balancing each radiator in turn - i don't know what order they are in and do not have a radiator thermometer? Or, could the rad "just" need a clean?