Wiring Combi to RF Stat

[M.Joshi]

As you said in post 18, remove the existing timeclock:

You need to bridge CI & CL. No link across RI and & RL.

Take the supply for the thermostat receiver from CL and CN.

RL to A on the receiver
RI to B on the receiver

What I meant earlier was that the terminal block with all those connections is X2.

 

[M.Joshi]

Link between live and A

I don't think you need to link live to A as RL (which is connected to A) is already connected to live inside the boiler when you bridge CI and CL.

I've just drawn this - hope it helps explain:



If you can't see the above image very well, try this link:

http://tinypic.com/r/2j2ardw/6

 

[Nat]

Thanks M. Joshi. Very kind of you to go to the trouble

 

[M.Joshi]

Thanks M. Joshi. Very kind of you to go to the trouble

No problem - one thing I should have made clearer is that the link across 2 & 3 is what you will link across CI & CL on the terminal block.

 

[Nat]

Many thanks to those who replied. Did this job this morning and all went well. Easy when you know how!

 

[M.Joshi]

Glad it all went well!

 

[mutley racers]

And what about the link from L to L in the receiver, is this still needed

 

[doitmyself]

And what about the link from L to L in the receiver, is this still needed

The two L terminals are already connected internally.

Did you mean L to A?

If so, it all depends on which boiler you have.

Some boilers use mains voltage control; other use low voltage control.

If your boiler uses low voltage control (sometimes called 'Volt-free'), you must not connect L to
A. you wil always need four separate wires to L, N, A and B.

If you have 230V switching you can use four wire or three wire, in which case L is connected to A.

 

[mutley racers]

I didn't know they were connected internally in the receiver. How can you tell this from the wiring diagram? Would love to know how to read them.

I know you don't need to link L to A as it is done in the boiler Co to CO if I am not mistaken?

 

[mutley racers]

I have to do to the boiler in thread. But, I tell you what, great explanation of the volt free and 240. So if it was volt free, I wouldn't branch Co to CL?

 

[doitmyself]

I didn't know they were connected internally in the receiver. How can you tell this from the wiring diagram? Would love to know how to read them.

1. The wiring diagrams do show the two terminals connected internally. Look at the diagrams again - inside the BDR91.

2. If the two terminals were not conected together, I would expect them to be labelled differently, e.g L1 and L2.

3. You can always use a meter to check continuity between the two terminals.