Arrived back late after 3 weeks away. Fired up central heating and went to bed. Next morning I noticed the radiators were cold. Hot water is fine. Fiddled with the room thermostat and could hear it click on and off.
Fiddled with the main timer (On/Once/Twice/off) and could hear the pump start up.
Discovered the Actuator (Drayton TA/M4) with lever pointing to 'Hot water' and not 'Heating'. Nothing I did to the other heating controls seems to make a difference to this setting or to get the lever to move.
I tried moving the lever by hand but could not move it and did not want to try to hard and maybe break something.
1. Any thoughts on the problem of cold radiators?
2 Am I supposed to be able to move the metal lever on the actuator from 'Hot water' to 'Heating' and will that solve the problem
3 How hard can I reasonably force it
And any other helpful ideas you may have
Thanks in advance
Sounds like the valve has seized.
You could try more force on the actuating lever but I think these are plastic and it's easy to break them inside the head. If the head is removable take it off and try operating the valve directly.