Changing room thermostat for WiFi

17 Jul 2013
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United Kingdom
A simple question. Can I replace my existing Honeywell T6360B wired thermostat with the Honeywell CM721 or 921 WiFi model.

The reason for doing this is to relocate with minimum disruption.

My existing stat has three wires. Will I only need to use two of them when I wire the receiver.

My boiler is a Potterton Kingfisher RS60 model
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It is easy but you can't use the existing 3 wires.

Put the receiver box in the airing cupboard and disconnect the wire running off to the old stat.
Many thanks Dan. I understand that the existing wiring will be redundant, my query was regarding the wiring. Do I now only use two wires for switching at the. Receiver, that's apart from the 240volt supply, and ignore the third wire.
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Sorry to be a pain, but the existing wiring is three wire and earth. Is it not possible to use the existing wire and just move the wires around in the connection box next to the boiler, and then I can site the RF receiver in place of the existing thermostat.
If it is 3+e then yes.

Live and neutral (1 & 2 on your old thermostat) to L (left of the 2) and N.

Link the right L to A and then the wire on 3 goes to B.

Then simply leave your current programmer on constant for heating, or move the heating on wire to a permanent live.

Leave the earth wire tuck up safely inside the receiver box with a line connector on the end.
Looking at the diagram for the RF receiver. It looks like the same wiring, regardless of direct boiler or zone valve. Is my thinking right.
My existing live wire comes from a terminal black marked "CHO" and this is controlled by the programmer. Could it not say in that position.

If I put the wire as suggested into a live feet, or place the system on constant for heating, will this not leave the heating on 24 hours a day.
The cm92x is programmable. So the existing programmer is not needed for heating.

You need to power the bdr all the time.

Hence either leaving the heating on constantly or moving the wire.

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