Honeywell T40 room thermostat

Innys

Hello everyone

I think I may have a problem with the room thermostat for my central heating. When I switch the CH heating on at the programmer, the condensing boiler doesn't fire up. However, when I switch it to HW, the boiler switches on.

I have turned the dial on the thermostat both clockwise and anticlockwise, making it click but the boilder still doesn't fire up. All the electrical connections to both the boiler and thermostat seem fine.

Any ideas where I could be going wrong?

Thanks

diable

It could be the valve sticking..

Innys

diable wrote: »

It could be the valve sticking..

Spot on. I fiddled arond with the manual override on the valve which seems to have kicked it back into life.

Undoubtedly it will happen again but it is less urgent than it was.

diable

Sometimes a light tap with a pair of pliers helps but it could be on its way out so keep an eye out on it.

1984ReturnsForReal_2

Innys wrote: »

Spot on. I fiddled arond with the manual override on the valve which seems to have kicked it back into life.

Undoubtedly it will happen again but it is less urgent than it was.

Most probably as said it is the valve or just the valve control.

You might be able to buy the actuator head if its a newish valve but you can just replace the internal motor.

http://www.screwfix.com/prods/28670/Plumbing/Central-Heating-Controls/Drayton-Synchronous-Motor

With the electrics off put a multimeter across the motor & if you dont get a connection just replace the motor.