Changing Honeywell Room Stat for a DT90E Help and information on all topics relating to your central heating, air conditioning and ventilation issues.

[pollypetee]

Quick question guys.

I have picked up a DT90E from my local screwfix with no instructions (last in stock...)

I currently have an old honeywell with 4 wires connected:

earth
black to no2
grey to no3
brown to no1


It has A, B and C
Can anyone shed some light here for me please.

Boiler is Vailant Eco

Cheers in advance peeps.