How to Replace a Honeywell Heat Pump Thermostat

Turn off the electricity for the heat pump or other HVAC systems that will be connected to the thermostat.

Remove the cover from the old thermostat.

Make a note of which wires are connected to which terminals on the thermostat panel.

Disconnect the wires from the thermostat with the screwdriver or by pressing on the terminal to release the wire, as needed.

Use a screwdriver to loosen the screws on the subpanel. Pull the subpanel off the wall. Carefully pull the wires through the back of the subpanel.

Place the template on the wall, on Honeywell thermostats supplied with one, and mark out the holes for the thermostat. If your thermostat didn't come with a template, hold the thermostat on the wall and trace around it with a pencil. Measure the distance on the back of the subpanel from the side to the holes in the back. Transfer this measurement to the tracing on the wall. Use a power drill to make holes in the wall. Insert plastic anchors.

Feed the Honeywell heat pump thermostat wires through the back of the subpanel.

Connect the wires to the appropriate terminals on the thermostat. The exact connections will differ with each model. You may need to use the wirestrippers to cut off the last quarter inch or so on the wires in order to connect them.

Place the subpanel on the wall so that it lines up with the pre-drilled holes. Insert screws through the back of the subpanel and into the anchors. Secure with a screwdriver.

Slip the cover over the subpanel and snap into place.

Restore the power supply.