How to wire in a new room thermostat

[eyespy999]

Good morning.

I have a Siemens room thermostat which has two wires inside. I bought a siemans rdh10rf set digital room stat which seemed
I've a good Idea at the time.

I thoughtbit would just be simple taking the old one off and connecting the new one on. However when I connect up the two wires nothing works.

Can anyone assist with some advice please I have attached photos of old and new.

Thanks

Ps having issues uploading photos boiler is a Chaff Britony system plus 100

 

[namsag]

you need a separate live and neutral to the receiver as well as the 2 wires that go to your existing roomstat,

So fit receiver by your boiler take a live and neutral from your existing fused spur into it . Then locate the wire leaving your boiler to room stat and connect them to the correct connections in the receiver (of top of my head Lx an L1)

 

[eyespy999]

Thanks for the advice I will take a look.

Cheers

 

[doitall]

Check the boier manual to make sure it can take 24v and not need volts free.

 

[Agile]

I would expect the receiver will have volt free switching contacts so that it will not be relevant what the boiler is applying to its call for heat contacts.

Tony