Central heating pump

Keggers74

Our house has a gas fired central heating and hot water system that does not have a separate hot water vs. central heating controller. I.e it is either on or it is off.

The boiler is on the ground floor, with pump next to it. The storage tank is on the first floor and the two gravity supply tanks are in the attic.

During the summer I have turned all of the radiators off at the radiator valves so that it heats the hot water cylinder but doesn't warm up the radiators. The last few weeks some of the radiators have started to heat up even though the valves are turned off.

My question is, should the circulation pump still be turning on when the boiler is turned on to heat the storage tank, even though I have all of the radiators turned off, or will the boiler feed the hot water tank without the pump once all the radiators are turned off?

Am wondering if the pump is trying to force water through the closed radiators as it has nowhere else to go.

Thanks

shane0007

Either rads are not fully turned off or sludge in the system has prevented them from fully closing, but either way it is a rad valve issue.

Keggers74

Thanks Shane. So the fact that the pump continues to operate while the rads are turned off is ok, and the issue will be related to one of the problems you are pointing out?

Related issue is that the hot water tank isn't heating properly, so suspect there may be a blockage or air lock there and the pump has nowhere else to pump the water other than through the rads (other than any hot water it is managing to get through the tank).

shane0007

Could be sludge blockage, could be many things. Make sure the balancing valve on the cylinder coil is not switched off first.