I have a honeywell DT90E attached to my Vokera Option boiler. It has been working fine until last night when the heating came on and stayed on. The thermostat is set to 21 but it continues to heat the room (it got to 28 last night!). I have checked the wiring, reset the unit, changed the batteries and now have no idea what on earth is going on. Any help would be greatly appreciated.
Honeywell DT90E suddenly not working
- Thread starter blobbi
- Start date
Sponsored Links
Have you disconnected the wiring to the thermostat and proved that the boiler goes off? You also have on/off switches on the boiler to stop the heating.
Disconnect one of the wires in the unit.
If the heating goes off. Dead thermostat.
Otherwise it is a boiler fault.
If the heating goes off. Dead thermostat.
Otherwise it is a boiler fault.
Sponsored Links
DIYnot Local
Staff member
If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Are you a trade or supplier? You can create your listing free at DIYnot Local
