Got hot water but no heat Help and information on all topics relating to your central heating, air conditioning and ventilation issues.

[Janeym]

I have a back boiler - Gloworm of some description - which works ok. Thermostat in hallway downstairs clicks when turned up to higher temperature and the control unit in the airing cupboard shows both hotwater and central heating as being on BUT I have no central heating to the house, up or downstairs. Plenty hot water, but if I turn off the water and turn on the heating manually, there is no sound fom the boiler whereas normally it would fire up. Please help, I'm freezing!
Thx :(

[htg engineer]

Is this a fully pumped heating system ?

Sounds like a problem with the actuator/3 port valve.

[The Heating Doctor]

I think it's the end switch in the motorised valve on the heating side. When your motorised valve gets to it's full open position a switch is closed, this closed switch in turn fires the boiler. The switch wires are the white/ orange wires but these colours can vary depending on make. If a Honeywell, ACL, Drayton, Sunvic and some others the head (known as a actuator) can be changed with out draining down the system. If you are ok with electrics my suggestion of the fault can be checked by going through the wiring.