Isar HE30 & Honeywell CM907 electrical connections

[mooney3]

Hello, advice needed.

I am replacing my Honeywell HC60NG & CM31NG with a Honeywell CM907 but I need some assistance with the electrical connections.

In situ at the moment is a 3A fused switch (See photo) to which the Earth brown and black from the Isar HE30 are connected. The Grey is linked to an extension to form a straight run.
The Black and the Brown then come back out of the 3A fused switch and along with the Grey linked connect into the back of the HC60NG
The Black went to N, The Brown went to L, there was a Red link between the second L and the A, and the Grey linked went to B

I have removed the connections from the HC60NG but need to know how I wire up my New Honeywell CM907

Please see the photos of the electrical connector at the Isar boiler and also the unconnected wires at the switch end.

Any advice appreciated

Paul[/img]

electrical connection to Honeywell CM907

• mooney3
• 26 Jan 2012
• 2

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[mikely]

I am a bit confused because as far as I can tell, the HC60NG is a wireless receiver and the CM31 is a wired programmable stat.

However, assuming that the HC60 was controlling your system:
Connect the Brown that went to the HC60 L to the CM907 terminal ‘A’
Connect the grey that went to the HC60 ‘B’ to the CM907 ‘B’.

 

[mooney3]

Sorry Mikely, sausage finger typo error. It is in fact a CM61NG programmable thermostat and not the CM31.
I will try as you suggest but does that mean I blank off the Black wire with a connector box ?

Regards
Paul

 

[mooney3]

Hello Mikely, boiler now up and running with programmer.

Thanks

Paul