Honeywell T6360B Wiring to Replace Old Honeywell Thermostat - Advice Needed Help and information on all topics relating to your central heating, air conditioning and ventilation issues.

[tomguest]

My old honeywell thermostat has broken. I'm going to replace it with a new T6360B. My broken thermostat (off the top of my head is the same model but without the led indicator) only has the terminals 1 & 3 wired to the control board (see attached picture).

Do I only need these two terminals or do I also need to wire in terminal 2? The current wiring has been made such that adding a third wire at the thermostat end is going to be a bit of a nightmare.

[ericmark]

Mechanical thermostats normally have a resistor to warm it up slightly to reduce the time between switching on and switching of to reduce the hysteresis.

However often the main control is the thermostatic radiator valve (TRV) and all the wall thermostat does is to turn off the system in warm weather.

So as to if the neutral is required or not is down to what your using the wall thermostat for.