How To Remove Thermostat Battery. First, turn off your power to the ecobee connected furnace. Open the battery compartment and remove the batteries;
Turn the thermostat off and remove the batteries. Just press and pull the cover to take out the battery compartment from the top right corner. First, turn off your power to the ecobee connected furnace.
The batteries are exposed two in front and one behind.
Honeywell thermostat won’t work after replacing batteries. The thermostat comes with a sliding battery compartment and you do not have to open the cover from the base plate to replace the battery. Disconnect battery, drain coolant, remove hoses; Pay attention to how the wires are attached to the old thermostat for future reference before you remove them.