How to Wire a Furnace Thermostat

What You'll Need
Wire cutters
Wire stapler
Wire strippers
Power drill and small screwdriver
Plastic anchors for drywall

Your furnace thermostat is an essential part of a home furnace system. The thermostat is responsible for regulating the other systems inside the furnace; it is primarily in charge of maintaining temperature.

If the thermostat is not working properly, you may find that your home is colder or warmer than you would like it to be. Your electric bill may also shock you, as the furnace may be overworked. Read on for a brief and comprehensive guide on how to wire a furnace thermostat.

Step 1 - Prepare the Furnace

First, turn off the furnace. Most furnaces have a power switch in the central control or the heating system. If the wire is not already connected to the furnace, connect it to the proper terminal according to your furnace owner's manual. Run the wire through the furnace covering and into the control panel where the thermostat will be located. If there is not an opening in the control panel, you will need to cut one on your own.

Step 2 - Install the Thermostat

When you have decided where the thermostat will sit, you can install it in the drywall. Mark the location where you want to install the thermostat. Drill a small hole in the drywall in that area, then feed the wire into the hole.

To install the thermostat itself, use drywall anchors. You'll need to make sure that the thermostat is level, then use the screwdriver to install the drywall anchors. When those are installed, you can mount the thermostat on the anchors so that it will be supported by the drywall.

Step 3 - Connect the Wires

Most thermostat systems have two wires. One is red, the other is white. Strip the casing ¼ inches from both ends of both wires. Install the white wire on the thermostat and the furnace terminals that say "W." Connect the red wire to the thermostat and the furnace at the terminals that are marked "R."

Step 4 - Secure the Wires

You'll need to run the wires between the thermostat and the furnace, inside the walls of your home. Rather than allowing them to rest between the two terminal connections, it is better to use a wire stapler to attach them to the studs and other beams in the wall. Doing so ensures that they are safe from unnecessary damage. That will result in much less maintenance work for your furnace.

Once you've completed the wiring procedure, turn the furnace back on. Set it to the desired temperature. Wait for approximately an hour to determine if the furnace is working properly according to the thermostat reading.