Why is my thermostat not working?

January 12, 2023by admin
thermostat not working

A blank thermostat may not be a catastrophic problem, but it can be very frustrating. If not addressed quickly, it can lead to more costly issues.

Listed below are some common reasons why your thermostat screen is blank.

Power surge or tripped breaker

If you return home from work and discover your thermostat screen is blank, a power surge may have occurred. In most cases, the thermostat just needs to be rebooted, however, the process to reset the thermostat varies depending upon the model. Some models have a tiny reset button which can be pressed with a paperclip. Others need to be reset by flipping the breaker in the panel box.

A tripped breaker can cause the thermostat screen to be blank. Try resetting the breaker and allowing the thermostat time to reboot.

A Safety Switch is Open or Tripped

High-efficiency systems, heat pumps, and air-conditioners have condensate safety devices to prevent extensive water damage in case of a drain issue at the indoor unit inside your home.

Your indoor gas furnace or air handler should be fitted with a drain pan overflow safety switch.  This switch is attached to the emergency drain pan under the indoor unit and coil.  If the condensate drain becomes clogged, the drain pan can fill with water causing the safety switch to open or trip.  This will kill power to your heating and air conditioning system to prevent the water from overflowing and causing damage to your floor or ceiling. This will result in the system shutting down and causing the thermostat screen to go blank.

If you see a blank screen on your thermostat, the best recommendation is to contact your local, trusted HVAC professionals at Patterson Heating & Air Conditioning. 

Dead batteries

Many residential thermostats are powered by your home’s primary electrical supply. Some require batteries for proper operation and should be changed at least once a year.

If your thermostat screen is blank and it runs on batteries, replace them.

Open furnace door safety switch

Furnace control panels are outfitted with a safety switch. When the furnace door is removed, the safety is engaged and will shut down the system.

If the furnace door is ajar, or not attached firmly, the safety switch can cause the thermostat to be blank and the system will not engage.

Wiring connection issues

Another cause for a blank screen could simply be that the thermostat has gone bad. You can visually inspect the wiring connections by turning off the power to the thermostat, removing the panel and looking for any burnt wires. Dust can become trapped inside the panel causing a connectivity issue.

You can use compressed air, sparingly, to remove loose dust. Reinstall the panel on the thermostat and turn the breaker back on.

If this does not resolve the blank screen, contact your local heating and air-conditioning contractor for a service call.  Contact us now, we are here to help with all your HVAC needs. 

Thermostat needs to be replaced

Like most electrical components, a thermostat will not last forever. The average life of most brands is ten-years.

If the screen is blank on your thermostat and it is an older version, consult with your HVAC service technician to see if yours needs to be replaced. Some of the items mentioned in this article could be a result of an underlying or potentially bigger problem with your heating and air system. 

The best way to ensure your thermostat and equipment are working at optimum level is to schedule preventive maintenance with your trusted HVAC contractor.

Find Us On

Best AC Repair Companies in Charlotte

Patterson Heating & Air Conditioning Proudly Serves

Charlotte | Cornelius | Huntersville | Concord | Pineville | Fort Mill | Indian Trail | Myers Park | South Park | South End | Ballantyne | North Davidson | The Greater Charlotte Area

3922 Greensboro St.
Charlotte, NC 28206


(704) 610-1489