Replacing my old Thermostat with a Honeywell DT90E - Thermostat not Switching off
Posted: Sat Jan 02, 2016 9:07 am
I am also replacing my old thermostat with a Honeywell DT90e. It has 3 wires Black Brown and blue.I connected the brown to A the blue to B and and isolated the black. The thermostat does not switch off when temperature is reached.What have I done wrong please?