No Power To Rc Wire Detected Nest - This occurs mainly due to extremely hot temperatures, burnt fuse, low voltage to the rc wire,. Try running your old thermostat with the batteries removed. If it doesn't power on, your c wire isn't connected at the air handler. Did you ever find out the problem? My north system suddenly started reporting no power on rc wire. I tested the red rc wire to the blue common wire and there. Look and see if maybe there is a float switch in drain and if so lift the float to see if we get power to the nest. I donโt see a float switch. It would be in the main drain line or an overflow pan under. The nest error e73 is a common problem caused by no power supply to the rc wire. This occurs mainly due to extremely hot temperatures, burnt fuse, low voltage to the rc wire,. Try running your old thermostat with the batteries removed. If it doesn't power on, your c wire isn't connected at the air handler. Did you ever find out the problem?
This occurs mainly due to extremely hot temperatures, burnt fuse, low voltage to the rc wire,. Try running your old thermostat with the batteries removed. If it doesn't power on, your c wire isn't connected at the air handler. Did you ever find out the problem?