You have to count the number of wires. I failed to change the thermostat for my heatpump, because there were 8 wires connected to my old thermostat. The new thermostat I got from homedepot has only 5. I had to give up then. Fortunately, the utility company has a energy saving program which installs a digi thermostat for free.
【在 m****o 的大作中提到】 : You have to count the number of wires. I failed to change the thermostat for : my heatpump, because there were 8 wires connected to my old thermostat. The : new thermostat I got from homedepot has only 5. I had to give up then. : Fortunately, the utility company has a energy saving program which installs : a digi thermostat for free.