Combi boiler making noise even when no call for heat

[spannered]

Hi all,

Just after a bit of advice. I'm not sure if this is normal or if the boiler has always been this way, I've only noticed as I've been preparing to fit smart TRVs to some of the radiators in the house and need the boiler to be set to constant to be able to heat rooms on demand.

I have a Logic code combi 26 that's about 12 years old. When CH is set to constant, the burner fires up when the radiator calls for heat and goes off when not required. However, the pump (I think) never stops making a noise as if it's circulating constantly. It doesn't go off after a few minutes and will run all day unless the heating is set to off or timed. This also happens if no radiators are on and the CH is set to constant - the burner stops off after a minute or two but the pump (?) never goes off.

Is this normal?

 

[cross thread]

Sounds like the boiler is only switching off because it’s hot,so pump stays running,is it not wired so the valve heads switch boiler on,off rather that the valves just opening .

 

[spannered]

Sounds like the boiler is only switching off because it’s hot,so pump stays running,is it not wired so the valve heads switch boiler on,off rather that the valves just opening .

Thanks, I'm not sure what you mean - are you saying this is behaving as it should?

 

[cross thread]

No ,smart thermostatic heads should switch the boiler on/ off ,are yours just opening and closing without switching the boiler