I have a boiler in the basement, with two thermostats, one in the basement, and one on the first floor.
The first floor thermostat is working with a Google Power Connector, with it being connected to the COM port on the Taco SR503 board, and the old wiring connected to W and R and everything is working fine.
The old basement thermostat used to only have R and W but the thermostat wiring has a third unused wire. Everything seemed OK with just the R and W connected to the Nest Thermostat, but we don't heat the basement much so I think I need a C wire working.
I connected the C wire to the COM port on the Taco SR503 board (next to the other thermostat). However, now the Nest Thermostat says the R wire isn't connected but the C is. If I short the W and R wires (without turning off the power), I can hear clicking near the boiler. If I put the Nest Thermostat back on now, it says both W and R are connected, but now the C wire isn't connected.
If I shut off the power, the same thing happens.
If I put the W and R in the wrong way, the Thermostat says all wires are connected, but I can hear clicking from the boiler like it is being turned on and off repeatedly (I turned this off quickly).
None of this really makes any sense to me. Any suggestions would be helpful!
