Fitting a wireless room thermostat

[stevesgc]

Hi. Can anyone help with my query?

Currently I have a standard wired Drayton RTS room thermostat in the hallway and I wish to replace it with one of the new wireless types. The reason is because the location of the stat at the moment gets the house warm, but not the living room. This because it always switches the heating off before the radiator in that room (last on circuit) gets hot enough to provide sufficient heat. I have looked at moving the stat into the living room but it seems tricky with running the wiring. So I thought that a wireless stat might be the best solution, as I can put the controller module in the optimum position in the room without the hassle.

Now here’s my problem. My Drayton stat just works from 3 wires- Live & Neutral and a switch line or call for heat. Now I have looked at several makes of wireless thermostats - Honeywell, Siemens, Drayton - and it seems that usually the receiver module needs to be connected up with 4 or more wires - a separate Live and Neutral and wires for the switch feeds.

Is it possible that I can just replace the Drayton stat with a wireless type and connect it up using the existing 3 wires or do I have to completely reinstall with additional wiring?
The boiler we have is a Potterton Kingfisher 2. Thanks. Steve

 

[Homesafe]

maybe you can try balancing the system

or if you choose to go wireless, then the reciever is wired into and next to boiler so your old one cable is not useable.

you need 4 core iirc. instructions can be a pain sometimes.

 

[bengasman]

A rf roomstat has 4 wires; L + N, and 2 switch wires. You stick the receiver near the boiler as newgas said, so you don't need anything else.

 

[D_Hailsham]

Is it possible that I can just replace the Drayton stat with a wireless type and connect it up using the existing 3 wires or do I have to completely reinstall with additional wiring?
The boiler we have is a Potterton Kingfisher 2.

The simple answer is YES.

Connect the Live and Neutral wires of the old thermostat to the L and N terminals of the receiver. Connect the switched live to the "call for heat" terminal (B on Honeywell, 3 on Drayton SCR)
Link L to common (1 on Drayton SCR, A on Honeywell)


But as newgas says, you should try balancing the system first. I had a similar problem to yours in my last house - same boiler coincidentally. It was a large Edwardian semi spread over three floors. The thermostat was in the hall which also housed a very large radiator,which was expected to heat the hall, stairs and two landings. The result was the hall got hot and the boiler shut off before the TRVs in the other rooms could work. I solved the problem by shutting down the hall radiator a bit at a time until the hall was the last place to reach temperature.

If you want to try balancing read How to balance a CH system

Note to Newgas and Bengasman

You only need four wires if the boiler has "volt-free" switching, i.e. not mains switching. The OP has a Kingfisher which is 240V.

 

[bengasman]

You only need four wires if the boiler has "volt-free" switching, i.e. not mains switching. The OP has a Kingfisher which is 240V.

And the importance of the model of the boiler is.........