Hello.
I've got CM921 thermostat off eBay but I don't know how to connect it without damaging my boiler.
From boiler point of view there are few connections :
CN,CI,CL,RN,RI,RL
From thermostat relay box are:
N,L,L,A,B,C,D,E
I haven't got a clue how to marrie relay box with...