Honeywell Thermostat Backlight Not Working: How to Fix

While Honeywell Thermostats are known for optimal functionality and long lifespan, they sometimes malfunction along the way. And one of the common problems you may face with your Honeywell Thermostat is a faulty backlight.

If that sounds like you, then you want to continue reading as this post contains troubleshooting tips to help you fix the problem.

Let’s head right into it!

Tips to troubleshoot Honeywell Thermostat Backlight Problems

1. Restart the Thermostat

Though you want to have a professional to check and fix your faulty thermostat, a backlight issue is something you can fix yourself. So if your Honeywell Thermostat backlight doesn’t light up, the first troubleshooting step is to restart it.

How to restart your Honeywell thermostat? Simply remove the batteries and wait for about 10 seconds before putting them back.

This should restart your thermostat and get the backlight working properly again. But if it doesn’t, try the next troubleshooting step.

2. Check and Replace the Batteries

Most of the latest models of Honeywell thermostats run on batteries. If you have also gotten one of those and the backlight suddenly stops working, chances are the batteries are low/completely drained.

So check to see if the batteries are low and get them replaced.

Keep in mind that Honeywell Thermostats are of different models, so be sure to get the right batteries for your model. All Honeywell battery-powered thermostats use non-rechargeable alkaline batteries—lithium batteries are not recommended.

So ensure you get the required batteries as incompatible batteries may cause your device to work below its best. It may even bring you back to the same backlight issue.

With that being said, if your thermostat backlight is still not working after replacing the batteries, see the next troubleshooting step.

3. Check the Circuit Breaker

Your backlight may stop working because of a tripped circuit breaker. This may happen during a power outage or power surge in your home. So, check the circuit breaker to be sure it is not tripped. If tripped, manually flip it off and then on again.

Once you have done this, check your thermostat. If the power comes on, then the problem is solved. But if the circuit breaker trips again, it may indicate a more serious problem that requires a professional to help.

4. Check for Wiring Problems

If you have a hardwired thermostat, you want to check if the backlight issue is caused by a loose or burned wire. Note that your thermostat backlight won’t work if the backlight circuit is not receiving current.

To check for loose/burned wires, turn off the device and then remove the cover. Depending on your thermostat model, you may have to unscrew some screws to remove the cover from the wall, so get your screwdriver handy.

Next, carefully check the wires to see if anyone is loose/burned and reattach them properly to the appropriate terminals. To remove corrosion or improve a connection, use a wire stripper to expose a fresh section of the wire and then reattach it to the terminal.

Why is my Honeywell Thermostat Backlight Not Working

Once you have repaired any wiring issues, put the cover back and then turn the thermostat back on to see if the issue is fixed.

Keep in mind that fixing wiring issues may require some prior experience. If you think it’s something you can’t do on your own, get a technician to help you check and fix any wiring issues. The technician may also check and repair other causes of the backlight issue.

If your Honeywell Thermostat backlight is now working properly, congratulations! But if not, you may have to contact Honeywell for further help.

You may also consider replacing your thermostat depending on the lifespan.

Honeywell Thermostats Related Problems and Troubleshooting Tips

Why is my Honeywell thermostat display blank?

Blank display on your thermostat could be caused by:

  • Problem with the circuit breaker.
  • The heating and cooling power switch turned off.
  • Furnace door not securely closed.
  • Disconnected C-wire.
  • Wrong R/Rc slider set up.

To fix this problem, check and reset the circuit breaker, ensure the heating and cooling power switch is turned on, and also make sure the C-wire is correctly set. Also, check that the furnace door is securely closed and that the R/Rc slider is set correctly.

My Honeywell thermostat heating or cooling system does not respond—what to do?

Here’s how to go about this issue:

  • Set the system to Heat mode by pressing the Menu, System Mode, Heat, and then press Done to complete. Ensure your preferred temperature is higher than the indoor temperature.
  • Set the system to Cool Mode by pressing Menu, System Mode, Cool, and then Done. Ensure your preferred temperature is lower than the indoor temperature.
  • Check the circuit breaker and reset it if needed.
  • Check and turn ON the heating and cooling system power switch.
  • Ensure the furnace door is properly closed.
  • Now, wait for about 5 minutes for the system to respond.

Why is my Honeywell sensor not connecting?

To fix this issue, press and hold the Connect button on the wireless sensor for about 15 minutes. Wait for the LED to turn Amber. Next, return to your thermostat menu and press Menu, Devices, and then Sensors. Follow the instructions on the screen to add the sensor. This should fix the problem.

Final Thoughts

As you can see, there’s no specific cause of the backlight issue with your thermostat. Your Honeywell Thermostat backlight may not light up if the batteries are low/completely drained, or if any wire is burned/loose.

A tripped circuit breaker may also cause this problem. So, to fix this issue, check that the batteries are not low, check and fix loose wires, restart the thermostat, or get a technician to check for you.

Hope this article was helpful and you could get your thermostat backlight to work correctly again.

You may also read our article about fixing a Honeywell thermostat reading incorrect temperature and a Honeywell thermostat with faulty a heating system.