Replacing Honeywell T40 with Salus RT300 RF

24 Jan 2017
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United Kingdom
I was planning on replacing our Honeywell T40 room stat with the wireless Salus RT300 RF. Is it possible to directly replace the T40 with the RT300, or will I need extra wiring? The T40 has 4 wires; Live, Neutral and 2 that look like earth wires.

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The point of wireless systems is that you put the receiver near the boiler or wiring centre so that you do not need wiring to a location somewhere else in the house.

If you are going to simply replace your existing thermostat with a programmable one (assuming you have the required wires) then you do not need wireless.
Be careful as colour/function of the wires can vary depending on what cable was used so don't assume wires are live/neutral/earth etc... unless they have been tested with a multimeter etc.. As for replacing it, you say you have 4 wires so there's a good chance you can, but we need to determine what function those wires are having (and do they go directly to your boiler etc..).

Will you be doing the work or was just wanting to know if it can be done before buying it / getting someone in?

As EFLImpudence pointed out, having a wireless thermostat allows you to fit the controller/relay near to the boiler and not have any thermostat/boxes where the old thermostat is. Granted you might need to redecorate where the old thermostat was :cautious:
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