Replacing BDR91

I have got a BAXI 130HE combi boiler, my bdr unit is wired to A and B (no earth, plug in boiler). Am I right in thinking these should go A->CH Com and B->CH NO?


  • So, I have connected this as described, but tado won't switch the heating off whether I use app or thermostat. No valves were installed, so that's the only means to control the heating. Any ideas?