How to Wire a Furnace Thermostat

Your furnace thermostat is an essential part of a home furnace system. The thermostat is responsible for regulating the other systems inside the furnace and is primarily in charge of maintaining the temperature at the level that you set. If the thermostat is not working properly, you may find that your home is colder or warmer than you would like it to be. You may also be unpleasantly surprised by your electric bill, as the furnace may be working too much unnecessarily. Read on for a brief but 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 at the central control or the heating system. If the wire is not already connected to the furnace end of the system, 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 to 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, and 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, and 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 2 wires. One is red, and the other is white. Strip off the casing about a quarter of an inch 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 in between the thermostat and the furnace, inside the walls of your home. Rather than allowing them to rest between the 2 terminal connections, it is better to use a wire stapler to attach them to the studs and other beams in the wall. This helps to ensure that they are out of the way so that they avoid unnecessary damage. This will result in your furnace requiring less maintenance work.

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