Can the Evohome wireless relay box (BDR91) be used to switch on underfloor heating? (non-electric).
If so, can I have two such relay boxes connected to my boiler, one for the underfloor heating and one for the rest of the house?

I've just had underfloor heating installed with its own wireless thermostat and relay box, my plumber says connecting the evohome wireless relay box in parallel (so either of the relay boxes can trigger the combi boiler) is possible.
I'd like to know if I can replace the other relay box with a Honeywell Evohome one, so I can control both from the same controller (the controller that comes in the Evohome base pack).

I've attached photos of the setup so far for clarification (only the underfloor heating relay box is currently connected)