Advice on 'Clicking Noise' from one radiator

[Gary_M]

Hi, one of my radiators requires bleeding approx. once per 3 weeks. I removed it recently and flushed it out, so I am pretty sure that it doesn't have any build up of sludge and the problem doesn't lie here.

I notice that it often makes a 'clicking' sound around the same time as it needs bleeding. I am not sure if this might just be it heating up'/cooling down.

There is a new thermostatic valve, but the other valve is at least 10 years old. I don't notice any water coming from this valve, but wondered if it could still be the cause of the problem (i.e. letting air in slowly)?

 

[chrishutt]

Clicking sound will be air bubbles entering radiator. The source of the air is unlikely to be the radiator itself. Air is probably sucked in on the upstream side of the pump and/or where static pressure is low (higher parts of system).

 

[Gary_M]

Clicking sound will be air bubbles entering radiator. The source of the air is unlikely to be the radiator itself. Air is probably sucked in on the upstream side of the pump and/or where static pressure is low (higher parts of system).

Thanks Chris. Will check it out.