Central Heating and Boiler Will Not Turn Off

[smcuk]

Hi,

I have an Oil fired boiler pressurized System.

All has been working perfectly OK up until yesterday.

Now, The Boiler just keeps working all the time and keeps heating the house 24/7.

I have tried the following with no effect.

- The digital honeywell wall thermostat has no efffect anymore whether on or off showing boiler or not.

- The Standard Honeywell Controller (Sliders for CH and CW) has no effect. If I switch everythin off the system keeps running. I have also undone the little screws underneath and removed the complete unit from its wall mounted connections and this has no effect, the boiler and heating keeps going.

- I have checked the separate power feed to the froststat and disconnected that live wire but this does not help, the boiler continues regardless !

The only thing that works is to kill the complete power supply then thankfully the boiler stops.

I have to stress that there has been absolutely NO work on any electrics or anything, this has just happened from nowhwere !

Any ideas would be very much appreciated

Regards,

SMc

 

[kevplumb]

and the $65.000 question is

SYSTEM

 

[smcuk]

Hi,

The System is standard unvented with a Turkington Engineering Turco 2000 Outdoor System 70/90 Oil fired boiler, a motorised valve and honeywell control units.

Regards,

SMc

 

[Kristoflampie]

Motorised valve switch sticking/ stuck ............

 

[smcuk]

Hi,

thanks for that tip,

would that be the Central Heating Motorised Valve (Only 6 months old!) or could it also be the Water Motorised Valve ?

SMc

 

[smcuk]

Yep, looks like the CH motorised valve.

The heating has been switched off for over 1 hour using the mains isolation switch, however, the underside of the motorised valve is still too hot to touch with my fingers !!

Thanks,

SMc