Fixing Blank Screen on Honeywell Thermostats

Fixing Blank Screen on Honeywell Thermostats



Several factors may result in your Honeywell thermostat's screen being unresponsive or totally blank.

Below are the most common causes of blank screens:
  1. Tripped circuit breaker
  2. Dead Batteries
  3. Broken Thermostat Screen
  4. Power Loss
  5. Low Display Brightness
  6. Tripped Safety Switch
  7. Open Door Furnace
  8. Loose Wiring
  9. Damaged Thermostat
  10. The thermostat is OFF

Please see the recommendations below on how to troubleshoot a blank screen.

Check Thermostat Powering

Confirm that there is power to your thermostat and that the breaker has not tripped. You may also power cycle the thermostat.

Please follow the below steps to do this:

1. Ensure your HVAC system is not running. If it is, please turn it off.
2. Locate the switch for your thermostat in the breaker box.
3. Flip the switch to the OFF position for 20-30 seconds.
4. Return the switch to the ON position.

Inspect for Blown Fuse on the Electric Panel

If there a  blown fuse in the main electrical service panel, it may need replacement. Also check to see the loose wiring here. 

Inspect Loose HVAC Systems Connection

There may be a problem with the air conditioner, boiler or heater that has made the transformer stop sending voltage to run the thermostat. The wires used should be in the correct gauge and coltage rating as this may alter regular functionality.

Ensure the contacts are free of any foregn materials, rust or dust.

Replace Batteries



Batteries running out is a common issues with all thermostats that are battery powered. If the screen flickers or turns off completely, then batteries may be the primary cause.

If your thermostat is fully battery--powered, it won't work with faulty batteries.

Inspect for Loose Thermostat Wiring or Connection

Inspect all the wiring connection to ensure there are no loose connections/ screws.

You need to test and confirm that the R and C wires have power since are responsible for powering the thermostat. Confirm if your thermostat requires powering through the C-wire. Ensure that the thermostat is firmly and securely pressed on the mounting plate.

Check for Open Furnace Doors

Majority of furnaces have door switches. Some thermostats can stop working once they sense that the furnace door is open.

To make your Honeywell thermostat work properly, close the doors and turn on the sensors. 

Replace the Thermostat

If the issue persists, you may need a contact a service technician to investigate posibility of malfunction or damage.  This may also result from ageing. In this case, they can advise you on whether your site technician may have to fix the unit or replace it with an updated thermostat model.

It is advisable to have the wiring done by a certified technician to avoid any damage of property or injury.

Learn more on HVAC systems and controls in the link here.

Contact our HVAC Controls Engineering team for assistance with custom HVAC control solutions.

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