Too hot

[steveyboy1]

Hi , my Room stat wont switch off .It clicks but the neon light stays on and so does the boiler getting hotter .Only cure is to switch mains off/on.Changed room stat.This happens now and again.
Any suggestions ??????

Boiler
3 way valve
Cylinder and stat
room stat
pump
programmer

 

[Gas2Air]

It is likely your mid-position valve is stuck, see if you can see what manufacturer it is, i'm guessing potterton or llandis & gyr, depending on that, try taking the head off valve and see if motor goes back.

 

[steveyboy1]

Thanks , yes I thought the valve , just couldnt see how the led stays on the room stat.It must somehow put a live feed back on the thermostat from the valve.

 

[steveyboy1]

Oh , It's a tower valve.