How to Troubleshoot a Home Thermostat

Over time a home thermostat can begin to function strangely. You may notice that the furnace or air conditioner do not work at the right times. If you're heating and cooling do not seem to be working correctly there are several easy tips to try before calling in a professional. Troubleshooting a home thermostat can be done with basic hand tools and a in a short amount of time.

Things You'll Need

• Screwdriver
• Small paintbrush

Instructions

1. Verify your filters are clean and any hoses to or from the heating and cooling units themselves are in tact and free of wear.

2. Check that your thermostat is mounted level using a bubble level. Also verify it is mounted at a height of 5 feet. Being too low or high can be the cause of abnormal behavior.

3. Stand near the thermostat to check for any drafts or nearby hot or cool air sources. The thermostat should not be located near vents, windows, heaters, appliances, on outside walls, or anywhere else that doesn't represent the proper room temperature of your home.

4. Replace the batteries in the thermostat if you are using a wireless one. Use longer lasting lithium batteries.

5. Remove the thermostat cover, and then unscrew it from the wall. Feel inside the wall for hot or cool air that could be affecting your thermostat readings. Correct this problem by placing some insulation behind the thermostat before attaching it back onto the wall.

6. Clean out the dust inside the thermostat using a small, fine-bristled paintbrush. Also check the wire connections for corrosion. If any is visible, remove the wire to clean away the corrosion then reconnect the wire to the clean terminal.

7. Find the heat anticipator which is a small lever on a calibrated scale inside the thermostat. Adjust the heat anticipator level one click to the "longer" side of the scale if the furnace or air conditioner runs too frequently, or the "shorter" side if the furnace or air conditioner runs too long.

Tips & Warnings

• Place a thermometer that you know works next to your thermostat and monitor it to see if the temperature on your thermostat reads what the working thermometer says.

• Turn off the power to the thermostat when working on its internals. Do this by tripping the breaker that controls it in your circuit panel.

• Do not touch the interior parts of the thermostat with your fingers. You may damage them or you could be shocked.