Worcestor Bosch 42 cdi TD200/RT10 + Independent UFH Controls

[ojequier]

Hi,

I'm totally new to this site/forum so apologies if posting to wrong place.

I'd be grateful of any advice/knowledge on the following :-

I have a WB42cdi combi boiler controlled by the TD200 and RT10 room stat that power x number of rads around the house.

I am in the process of having an extension built that will use underfloor heating. The new area will have it's own stat, zone valve and pump.

I would like the new UFH to be able to call for heat independantly of the main stat. Normally, this would be a simple wiring job making either stat "close the loop" to turn the boiler on. However, the TD200 and RT10 operate on low voltage so are not directly compatible and I think both have to be calling for heat for the boiler to fire.

Can anyone suggest a method (3 party controls/different WB controls etc) that could help here?

I've looked at the manual for the WB and have noticed there are some "frost stat" connections on the board... I think these are 230v (not sure though) so maybe these could be used?

I’ve asked a few heating experts and indeed submitted the Q to Worcester Bosch but to no avail.

Can any one help me?!

Thanks in advance - Newbie

 

[Qualitykez]

Hi mate, just signed up to this forum looking for the exact same advice. Have you managed to sort out the problem? Iv tried numerous different avenues with no avail! Like you said the connections which fire up the boiler, fan, pump ect when the CH is called for all appear to be 24 vdc which are obviously not compatible with the UFH controls. Previously with different boilers and UFH systems iv simply wired the SL coming from the UFH into the same connection as the boilers CH timer thus simulating the timer kicking in but obviously this isnt as straight forward with the 42cdi as this connection is hidden under the pcb.

Let me know if youv had any joy,
Cheers