Thermostat Troubleshooting

If it is a cold Nashville night or a scorching afternoon in Murfreesboro and your HVAC system isn’t keeping up, check the thermostat first. A few things to consider:

Check the thermostat battery. If your battery is dead during a power outage, the thermostat reverts to its default settings and you’ll lose your programming.
Depending on the season, set the thermostat 5 degrees higher or lower than you normally would.
Check to make sure you’ve set it for “heat” or “cool” and see if the right system comes on.
Check to see if the circuit breaker for the unit is “on” and hasn’t flipped.
Turn the circuit breaker for the unit “off” while you inspect the thermostat.
Pry gently and remove the thermostat cover.
Gently blow out dust or debris. Make sure the thermostat is level and firmly attached to the wall.
Inspect the wiring and make sure each wire is firmly attached to its mounting screw. If necessary, reattach loose wires and tighten loose mounting screws.
Turn the breakers back on and repeat the 5-degree difference test. If the system does not come on, turn the power off at the breaker panel again.
Look at the wires again. If AC is the issue, unscrew the red and green wires.
Wrap the two wires together. If the system comes on, your thermostat is faulty.

Where to locate a thermostat

Location applies to more than real estate. The location of your thermostat affects performance and efficiency because the wrong spot creates “ghost readings” that make your HVAC system think the air is hotter or colder than it really is.

Keep your thermostat away from direct sunlight, drafts, doorways, skylights, and windows. Place it on an interior wall where warm air rises and cool air sinks naturally. Don’t put furniture in front of the thermostat because doing so blocks natural air movement.

If you use room air conditioners, don’t place lamps, TV sets, computers and other electrical appliances that emit heat near them. Their thermostats sense the heat, which can cause the AC to run longer than it needs to.