Betacom 24 and wiring in a wireless stat

[dav123a]

Current boiler has no stat of any kind. I've got a honeywell wireless stat to fit but I'm not sure what the connections are in the pcb. The boiler was put in around 2007 . I think the connections are either 3,4,5 . But there is already something in these going to the pcb. Or it could in place of a small length of cable that is the marked room thermostat that was coiled up behind the pcb. Can put a pic up if needed. I'm hoping someone can help as I'm slightly baffled by these connections.

[dav123a]

It's a honeywell cmt927 I've got . There is a timer on the left hand side of the board that's mains powered. Is the room thermostat cable just that , a short and it turns the heating on ? If so I take it I can connect to that and in effect the the wireless stat takes places of the what's there now. My concern has been getting the right voltages and could have a go but I'd rather not pop a pcb.

[dav123a]

Gc number is 47-019-04

[dav123a]

Cheers does it need a volt free closed contact to turn on or is there a voltage needed ? I'll have a look in the morning and see what's in m7.