Wiring a volt free stat to my new Heatline boiler?

[bobmankee]

We have fitted, a Heatline Monza 24KW condensing combi boiler. It has 24v and 240v connectors, although I'm lead to believe the 24v is just for the boilers built in controls.
The programmable thermostat is a Homexpert(Honeywell) THR870CUK, 7 day program, two wire, 'VOLT FREE' jobbie, that requires two AA batteries. It can be wired to 24v or 240v.
On the boiler there is a loop connector on the 24v 'RT' side which I have removed. On the 240v side there is a 'L' 'N' & 'E' for the mains, and on the same block 'RT' room thermostat and 'FP' frost protection.
The 'VOLT FREE' stat has two sets of terminals. First block has 'A' 'B' & 'C', the second block has '1' '2' '3' & '4'.
My question is this; where do I wire the 'VOLT FREE' stat? I'm begining to wonder wether I can only wire a mains volt stat to this boiler??
I'm guessing if it's possible I would wire it up as per 'BASIC BOILER' on the Homexpert manual, and wire 'A' from the stat to the 'RT' terminal on the boiler, and 'B' on the stat to the 'LIVE' on the boiler?

I can't post the links for the manuals, but they are easily found on google search.

Many thanks in advance for your help, as I'm at a loss.

 

[Mjcole_1210]

On normal honeywell wireless units they generally have 240v L and N terminals and ABC are the volt free terminals A being common and B normally open C normally closed. Ive seen a few boilers using 24v terminals to volt free but I generally stick to 240v as it saves on running extra cores. So to reiterate A and B should be your volt free switch contacts. Mike

 

[bobmankee]

So 'A' to the live on boiler and 'B' to the switch 'RT' on the boiler? I think the 24v controls are for Heatlines own controls. Do I need to leave the link wire in place on the 24v side?

I believe the wireless ones are wired up different as they require power for the wifi.

Thanks for your help. Matt

 

[Mjcole_1210]

I would say leave link out else it will think its demanding on the 24 v side. I supply permanent live to L and A then RT goes to B and you will need a neutral there too I would presume.
mike