Hi,
I am planning to upgrade my Honeywell T40 Thermostat to a T4. I believe the T40 is usually a two and the T4 is a two wire.
However I have 4 wires in my current T40, I believe I only use wires T1 and T3 into the new thermostat, which is straight forward.
My concern is that my current T3 which is the switched live is a grey wire and that my T2 neutral is a black wire, which looking at other pictures are the wrong way round? I have followed the wires back to the wiring box and they are wired the same way as the thermostat.
I just need confirmation, thee grey wire is ok to use. I do not have any problems with the thermostat or boiler, I would just like more functions.
I am planning to upgrade my Honeywell T40 Thermostat to a T4. I believe the T40 is usually a two and the T4 is a two wire.
However I have 4 wires in my current T40, I believe I only use wires T1 and T3 into the new thermostat, which is straight forward.
My concern is that my current T3 which is the switched live is a grey wire and that my T2 neutral is a black wire, which looking at other pictures are the wrong way round? I have followed the wires back to the wiring box and they are wired the same way as the thermostat.
I just need confirmation, thee grey wire is ok to use. I do not have any problems with the thermostat or boiler, I would just like more functions.