Radiator Pump on constantly

[madnurse3]

Oil fired Sealed system. Have Danfoss Heating control pack. Have 2 Danfoss HP22 2 port motorised valves, one for Hot Water ( HW ) one for Central Heating ( CH). Radiator pump is on constant, CH has not been on for weeks, but whenever turn on for hot water to be heated, the water is pumped round the radiators.
In the wiring box if I remove the " Grey Wire " from the HW Valve the pump stops.
I was wondering if I needed a New Valve or would a new Actuator or even a new Drayton Synchronous Motor. Any help would do.
Many thanks
Madnurse3

 

[ianmcd]

you seem to have diagnosed correctly/ try taking the synchron motor out of the valve , very easy to do but make sure you isolate the power first, if the mechanism springs back when you remove the motor then it was just the motor that was seized and quite cheap to buy, if it doesnt spring back you may need to replace the valve but this is possible but unusual

 

[madnurse3]

Oil fired Sealed system. Have Danfoss Heating control pack. Have 2 Danfoss HP22 2 port motorised valves, one for Hot Water ( HW ) one for Central Heating ( CH). Radiator pump is on constant, CH has not been on for weeks, but whenever turn on for hot water to be heated, the water is pumped round the radiators.
In the wiring box if I remove the " Grey Wire " from the HW Valve the pump stops.
I was wondering if I needed a New Valve or would a new Actuator or even a new Drayton Synchronous Motor. Any help would do.
Many thanks
Madnurse3

After removing motor and testing switch the spring back was very strong, so will change the motor first, system only 5 years old

 

[ianmcd]

yep sounds like the synchron motor had seized a relatively easy repair and the synchron motors arent expensive