Occasionally there is a gurgling noise in radiators even though no air is released when bleeding.

Also sometimes there is a clunk noise when the circulating pump stops.

Are the two related? What action can I take to stop them happening?

Thanks

DB60, February 2010

Unless its a velocity noise, ie- the force of the water being pumped through your rads, it must be air. The clunk may be a zone or diverter valve.

Henry, February 2010