Honeywell cm927 wireless thermostat help please

[ukpaul2011]

Hi all

Iam wanting to have a Honeywell cm927 wireless thermostat, on my glow worm betacom 30c combi(not my choice of boiler's lol)
I understand the 24v bit, but the 230v I thought I just connect it to the live feed into the boiler but have just looked at the boilers manual and it goes on about voltage connection on the pcb board,cut the loop(brown wire)and put a block connector the mains power thermostats muct be connected directly to the pcb.Here is the manual (page 36&37) hopefully someone can explane this to me as all I thought I had to do is connect the 24v up and leave the loop on the pcb alone

https://www.heatingspares247.com/do...owworm/Betacom_Installation_and_Servicing.pdf

Cheers
Paul

 

[twgas]

Do you have an existing timer and/or room stat?

 

[ukpaul2011]

Do you have an existing timer and/or room stat?

Hi
sorry no I don't have any timer or room stat
cheers

 

[Blagard]

Hi all

Iam wanting to have a Honeywell cm927 wireless thermostat, on my glow worm betacom 30c combi(not my choice of boiler's lol)
I understand the 24v bit, but the 230v I thought I just connect it to the live feed into the boiler but have just looked at the boilers manual and it goes on about voltage connection on the pcb board,cut the loop(brown wire)and put a block connector the mains power thermostats muct be connected directly to the pcb.Here is the manual (page 36&37) hopefully someone can explane this to me as all I thought I had to do is connect the 24v up and leave the loop on the pcb alone

https://www.heatingspares247.com/do...owworm/Betacom_Installation_and_Servicing.pdf

Cheers
Paul

I hope you didn't do that!!

 

[ukpaul2011]

Hi all

Iam wanting to have a Honeywell cm927 wireless thermostat, on my glow worm betacom 30c combi(not my choice of boiler's lol)
I understand the 24v bit, but the 230v I thought I just connect it to the live feed into the boiler but have just looked at the boilers manual and it goes on about voltage connection on the pcb board,cut the loop(brown wire)and put a block connector the mains power thermostats muct be connected directly to the pcb.Here is the manual (page 36&37) hopefully someone can explane this to me as all I thought I had to do is connect the 24v up and leave the loop on the pcb alone

https://www.heatingspares247.com/do...owworm/Betacom_Installation_and_Servicing.pdf

Cheers
Paul

I hope you didn't do that!!

I have not done nothing, until I get some advice on fitting it on here

 

[Blagard]

Your Boiler uses either a 24V thermostat or a 230V volt one not both.

Your CM927 has volt free connections meaning you can chose to wire it 230V or 24V on the thermostat switch. The big difference is if you go 24V switching then you must not link the 230V live as shown on most of the other setups.

Slightly confusing is the Combi - wiring diagram in the CM927 instructions actually suits the 24V switching diagrams in the Boiler manual. The direct burner control in the CM927 instruction suits wiring it 230V

Take your pick! one or the other

 

[ukpaul2011]

Your Boiler uses either a 24V thermostat or a 230V volt one not both.

Your CM927 has volt free connections meaning you can chose to wire it 230V or 24V on the thermostat switch.

Slightly confusing is the Combi - wiring diagram in the CM927 instructions actually suits the 24V switching diagrams in the Boiler manual.

Hi
Thanks for replying,
so all I need to do is connect the 24v up and leave the pcb well alone,
Does the CM927 needs a permanent live to power the box from the boilers fuse spur
thanks
paul

 

[Blagard]

This is important - TheCM927 is a 230V device so yes it needs a permanent mains connections Live Neutral and Earth to run. Do not connect any 230V to the switch terminals A,B&C

Using the volt free thermostat switch for 24V you need an entirely separate 2 core cable from the switch terminals A & B to the 24V at the boiler and yes you leave the boiler pcb alone.

 

[ukpaul2011]

This is important - TheCM927 is a 230V device so yes it needs a permanent mains connections Live Neutral and Earth to run. Do not connect any 230V to the switch terminals A,B&C

Using the volt free thermostat switch for 24V you need an entirely separate 2 core cable from the switch terminals A & B to the 24V at the boiler and yes you leave the boiler pcb alone.

Thank you, sorry am abit slow at this time off night
so if I connect T1 and T2 with 2 core wire to A & B
Then another piece of two core wire from the fuse spur to N & L on the box?
Cheers
Paul

 

[Blagard]

Thank you, sorry am abit slow at this time off night
so if I connect T1 and T2 with 2 core wire to A & B
Then another piece of two core wire from the fuse spur to N & L on the box?
Cheers
Paul

That's correct where T1 and T2 are the Terminals on the Boilers 24V Room Thermostat connector after removing the bridge.

When wiring 230V I think it best to use 3 core to keep the earth even if the device does not need it.

 

[ukpaul2011]

Thank you, sorry am abit slow at this time off night
so if I connect T1 and T2 with 2 core wire to A & B
Then another piece of two core wire from the fuse spur to N & L on the box?
Cheers
Paul

That's correct where T1 and T2 are the Terminals on the Boilers 24V Room Thermostat connector after removing the bridge.

When wiring 230V I think it best to use 3 core to keep the earth even if the device does not need it.

Great, thank you so much for taking the time to reply and explane
Paul