Replacing analogue roomstat with Honeywell CM907; wiring?

[alexp.1]

I want to replace my dial-type Eberle roomstat with a CM907 that I've just bought.

The CM907 just requires simple Live & Neutral connections. However, I took off the front of the Eberle and it had 4 connections; Live, Earth and two Neutrals (one N was something to do with a "heating load").

Can someone please tell me what I need to do with the wiring? Do the Earth and Neutral (Heating Load) wires become redundant, or do I put the two N's into the same connection block on the CM907? Cheers.

Boiler is a Baxi Barcelona system boiler and the CH/HW timer is a ChannelPlusXL H27 (on which the CH timing will become redundant as I'll just leave it to "On").

 

[kevplumb]

(one N was something to do with a "heating load").

that is the switched live back to the boiler the old stat will have an anticipater heater in it (i think)

 

[ELZ4742]

the cm907 is battery operated wireless system right?

does it not come in 2 parts?

 

[alexp.1]

the cm907 is battery operated wireless system right?

Nope, hard-wired

 

[alexp.1]

(one N was something to do with a "heating load").

that is the switched live back to the boiler the old stat will have an anticipater heater in it (i think)

Thanks, what do I do with it?!

 

[alexp.1]

does it not come in 2 parts?

Yep; back plate and fascia

 

[ELZ4742]

are you sure it doesnt have batteries? under the flap at the bottom

 

[ELZ4742]

they only need a live and switched live (old 1 & 3)--- A & B

 

[alexp.1]

Thanks.

Yes, it has two batteries.

Sorry to be dim; I know to connect old 1 to new A, but I'm still not clear what wire to put in new B. There isn't a 3 on the old unit, it has 1, 2, E & 4.

 

[alexp.1]

Okay; I'm going to connect Live (red wire) into Terminal A and the Switched Live (yellow sleeve) into Terminal B. May the force be with me.

 

[Nixt]

Sorry to be dim; I know to connect old 1 to new A, but I'm still not clear what wire to put in new B. There isn't a 3 on the old unit, it has 1, 2, E & 4.

Electrically incompetent might be a fairer self appraisal. Look at the wiring instructions that came with the unit. If you don't understand these or the way a standard 240V r/stat connects then wiring by proxy might prove difficult.




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[Nixt]

Okay; I'm going to connect Live (red wire) into Terminal A and the Switched Live (yellow sleeve) into Terminal B. May the force be with me.

Sounds promising.

 

[kevplumb]

make sure you isolate the neutral as well

 

[ELZ4742]

Okay; I'm going to connect Live (red wire) into Terminal A and the Switched Live (yellow sleeve) into Terminal B. May the force be with me.

that should be right, but boy do you live dangerously, please be careful!

 

[alexp.1]

Okay; I'm going to connect Live (red wire) into Terminal A and the Switched Live (yellow sleeve) into Terminal B. May the force be with me.

that should be right, but boy do you live dangerously, please be careful!

Installed it today. Only took 5mins. Lovely bit of kit.

Many thanks for the help.