Hi all,

So I've been having a good old play up in the airing cupboard today and got both my Evohome BDR91s now controlling the DHW and CH. I didn't want to do too much re-wiring so left the programmer in place - my wiring centre is one of the old Honeywell Sundial wiring PCBs where each component has it's own terminal block, the problem is with all the various links cut/uncut it's hard to know exactly how everything is connected, so I wanted to make as few changes as possible. In the end all I did was disconnect the room stat and cylinder stat and wired in a couple BDR91s in their place.

There didn't seem to be too much info about how to do this on the net, everything I found seemed to refer to the 10 way chocolate block approach, which was going to be my fall-back plan if I couldn't get this working. Fortunately I was successful, so I've knocked up a wiring diagram so that if anyone else is trying to find the info how to do this, well please see the pic below...

My system is Y-Plan and there's no guarantee this'll work for you, just merely sharing info for people who are searching...

add-evo-to-sundial.jpg