I have a potterton prt2 thermastat and want to replace it with a honeywell cm900 programmable my existing wiring is
The Potterton has 4 terminals/wires marked thus -
COM - RED WIRE
H - YELLOW WIRE
TL - RED WIRE
N- BLUE WIRE
COM and TL have a RED jumper wire to interconnect them
my boiler is just a conventional type.
the honeywell as
NLL ABC
so not sure from the diagram where the wires should go.
The Potterton has 4 terminals/wires marked thus -
COM - RED WIRE
H - YELLOW WIRE
TL - RED WIRE
N- BLUE WIRE
COM and TL have a RED jumper wire to interconnect them
my boiler is just a conventional type.
the honeywell as
NLL ABC
so not sure from the diagram where the wires should go.