Tuesday, March 11, 2014

Change A Home Furnace Thermostat

Installing a programmable thermostat helps you save on utility costs.

When you need to change your home furnace thermostat, you have two basic options: call a professional or do it yourself. Thermostats are connected to the furnace via wiring, so you don't have to work with the furnace itself. Depending on your setup, you'll have three or more wires connected to the back of the thermostat. With just a few tools, the thermostat can be changed out in minutes.


1. Turn off power to your furnace and air conditioning unit. Locate the correct breaker or fuse in your breaker box and either turn off the breaker or remove the fuse at the electrical panel.

2. Grasp the thermostat cover on each side and pull gently to remove it. Unscrew the mounting plate from the wall.

3. Label the existing thermostat wires. Each will be connected to a lettered terminal. Use each letter as the identification on the label.

4. Unscrew each wire from its terminal on the old thermostat. Wrap them around something like a pencil or pen when you're finished to keep them from dropping back into the wall.

5. Pull the wires through the new thermostat's base. Push the base tight to the wall and mark the mounting holes with a pencil once it's level.

6. Remove the base and drill a 3/16-inch hole at each marked location. Tap in the plastic anchors with a hammer.

7. Put the base panel back into position on the wall. Level the panel and fasten it to the wall with the provided screws.

8. Connect each thermostat wire to the appropriate terminal on the new thermostat. Refer to the labels when connecting the wires to ensure they're placed on the correct terminal.

9. Attach the thermostat to its new base by pushing it on until it snaps into place. Restore power to your furnace and air conditioner. Program the thermostat by following the instructions in your thermostat's manual.

Tips Warnings

If the new thermostat is smaller than the old model, chances are you'll have mismatched paint behind it. If this is the case, you may want to paint the wall before installing the thermostat.