Installing a wireless room thermostat

[stevesgc]

Hi . I would like to install a Drayton digistat RF601 wireless thermostat on our heating system, but can anyone please help with my query about the wiring for it.
Our boiler is a Potterton Kingfisher 2 and runs off a 240v supply. The system is a standard arrangement with a 3 way motorised valve, timer controls and pump. The current thermostat we use is a standard wired Drayton unit and has three wires going to it : Red - Live, blue - Neutral and yellow - Call for heat or Switch live. According to the Drayton RF601 basic wiring diagram in the instructions, the SCR unit has 4 wires – Live and Neutral, switched live to terminal 1 and a fourth wire in terminal 3 going to the motorised valve.
Can the SCR unit just work from the existing 3 wires? And if so how do I connect it up.
Many thanks
Steve

 

[simond]

I wouldn't fit an SCR if I were you, the Honeywell CM range is far better and more reliable.

You can leave the CH on your timer set to permanently on.

Then fit your SCR using L&N, as before , but also looping the live wire across to terminal 1. Use the the Yellow in terminal 3.

Alternatively, if you fit the Honeywell, loop the live wire across to terminal A and use the yellow on terminal B.

Using this method, the CH control on your programmer must be set to permanently on, putting the CH control in the hands of the programmable room stat, and leaving the radio receiver powered up.



As an alternative, change your timer for a new Honeywell unit incorporating a wireless room stat base station. Now that is clever.