You may need to. Your thermostat should pop.
How To Handle Nest Thermostat E74 Error Google Nest Community
No power to nest thermostat. Grip the metal ring of your thermostat and pull it gently towards you away from the wall. I have a bryant model 561cj060 h ac. The thermostat says there is no power to the rc wire. Some heat pump installations may have the auxiliary heat connection labelled as x w1 or w2 on the thermostat. I just installed a nest thermostat. Another reason why theres no power to the thermostat could be due to a bad transformer or even a faulty wire running from the thermostat to the transformer.
Remove the wire in the w1 terminal straighten it and put it back in as far as it will go. I had to turn read more. You should verify that the x wire on the old thermostat is not a common wire. Turn off power to your system at the breaker box or system switch. Turn off the power to your heating and cooling system at your breaker. When x w1 or w2 is an aux wire.
Nails pests like mice and rats and corrosion can all be a contributing factor. If your system works as it should with your old thermostat your nest thermostat may be damaged and needs to be replaced. There is a breaker box attached to it on the wall outside. If there is a common wire installed the nest thermostat will not power share.















