Honeywell CM927 Installation question

[jonnyfonny]

Thanks for the tip on the rechargeable batteries. Funnily enough we did swap out the originals for rechargeables (just to test) and it did seem a little worse.

I've tried rebinding on numerous occasions but to no avail.

I've attached the diagram from my parents boiler.

Thermostat wiring

• jonnyfonny
• 19 Jan 2011
• 1

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Now, from memory (I'm at work) I have it wired in like the diagram on the left. With a linking wire in the relay connecting L to A (I think).

Assuming I was to start from scratch and I was wiring in using 4 wires could one of you please explain exactly which terminals on the boiler connect to which in the relay.

I'm thinking:

RN-------N
RI--------B
RL-------L

But not sure about the fourth wire from A? Would that wire into CL? And if so would I then remove the link from CI and CL? Or keep it in place?

Thanks for your continued help and support.

Oh, if the relay box is faulty where exactly can I pick up a new one?

Cheers!

 

[D_Hailsham]

I've attached the diagram from my parents boiler.

Thermostat wiring

• jonnyfonny
• 19 Jan 2011
• 1

[/img]

Now, from memory (I'm at work) I have it wired in like the diagram on the left. With a linking wire in the relay connecting L to A (I think).

The relay needs a permanent supply to the L and N terminals. So it would be better to connect it to the L and N terminals of X1 (see Fig 7 on the next page of manual).

The link from L to A in the relay is correct.
Relay B connects back to RI on X2
Leave the link in place between CI and CL
Remove link between RI and RL

You only need three wires.

Oh, if the relay box is faulty

Before you write anything off, do the following:

1. Connect a length of cable with a 3 pin plug on one end to the L and N terminals of the relay.
2. Plug it in and carry out the binding procedure.
3. Put the relay out of the window.
4. Walk down the garden with the programmer, checking communication every few feet. This will tell you the open air limit. If it is less than 30 metres there is definitely something wrong.

As you have the same items yourself you can easily do a swap around to see which is the faulty component.

You should be able to order a replacement from your local plumbers merchant (not a DIY shed).

The relay is part no R6660D1041
The programmer is part no CMS921B1042