Potterton Puma 80e - after switching on hot water, hot water runs correctly but when turning off tap, boiler carries on heating until it overheats and pressure switch on central heating system blows (with steam coming out of the overflow pipe).
If after we use the hot water, i switch off then back on from electric mains this stops. If the hot water is not used, the central heating works fine.
Idea is - the heating body that deals with the hot water is not switching off after hot water tap is turned off. Got a feeling that the switching mechanism is not switching off hot water - how can this be resolved - or has anyone else had this problem and knows another reason why this is happening?
If after we use the hot water, i switch off then back on from electric mains this stops. If the hot water is not used, the central heating works fine.
Idea is - the heating body that deals with the hot water is not switching off after hot water tap is turned off. Got a feeling that the switching mechanism is not switching off hot water - how can this be resolved - or has anyone else had this problem and knows another reason why this is happening?
