i have worcester cdi 28 boiler, it was run off siemens wirelss that couldnt reach to lounge. i wanted to replace with simple thermostat control hard wired in. i took out the siemens base station which was wired into mains and to ls and lr on boiler. i connected ls and lr to l and sl on altech althcoo6. i didnt connect neutral and nothing worked, tried swapping over but still didnt work. the cable is normal domestic power cable with 3 wires and neutral, any ideas???