Troubleshooting
Thermostat Screen Blank or Dead: Troubleshooting Steps
5 min read••
When your thermostat screen goes dark, your HVAC system won't respond. Here are the common causes and solutions.
A blank thermostat screen means no control over your heating and cooling. Let's troubleshoot.
Battery-Powered Thermostats
Check the Batteries Many thermostats run on batteries. Replace them with fresh ones and see if the display returns.
Check Battery Contacts Corroded contacts can prevent power delivery even with new batteries.
24V Powered Thermostats
Check the HVAC System Power Make sure your furnace or air handler is powered. Check: - Circuit breaker - Furnace power switch (usually looks like a light switch) - Fuse on the furnace control board
Check the C-Wire Modern thermostats often need a common wire for power. If yours was recently installed, verify proper wiring.
Tripped Safety Some furnaces have a safety switch that cuts power if the drain pan overflows or the door is open.
After Power Is Restored
Factory Reset If the thermostat has power but acts strange, try a factory reset according to manufacturer instructions.
Reprogram Settings After power loss, you may need to set the clock and reprogram schedules.
When to Call a Professional
Contact us if: - You've verified power but the display is still blank - The thermostat works briefly then dies - You're not comfortable checking electrical components