Why Thermostats Go Blank Then Comes Back On

Thermostats are crucial in our daily life. They can help you control the temperatures of different rooms. Thermostats can easily go off or display only a blank screen. The problem can be quickly solved, but first, you must find the cause of the screen blankness. Once the thermostat becomes blank, it will be difficult to access the system to perform changes.

Thermostat going blank can affect the proper functioning of your thermostat. For instance, changing the temperature of different rooms will be impossible. Also, the heating and cooling units will fail to function. You must determine the cause of the thermostat blankness and try to troubleshoot the problem to make the thermostat perform its functions normally.

The reasons why the thermostat goes blank

why thermostat goes blank then comes back on
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Short cycling mostly makes your thermostat screen go on and off. The problem is usually due to heating conditions in the thermostat.

1. The thermostat is switched off

Failure to turn on the thermostat can cause the thermostat to go blank. Before trying to make any changes to the thermostat, inspect the thermostat and switch it on. In addition to that, countercheck your AC and ensure it is also turned on.

2. The thermostat batteries have died

Most of the thermostats require batteries to function. First, check your thermostat battery and know if it is the cause. If the thermostat goes blank and then turns on, try replacing the old batteries with the new ones. Further, try turning on the thermostat after replacing the battery to see if it is functioning well.

3. Check if the safety switch has been interfered

Check if the safety switch has been interfered

If the safety switch has been interfered with, it makes the thermostat go blank and then turn on. Check the safety switch to see if it has been damaged. The safety switch is mostly interfered with when the furnace overheats there, becoming too hot and damaging the safety switch.

4. The level of brightness is displayed on your thermostat

Some thermostats automatically reduce the thermostat screen brightness to dim. The dim brightness will make your thermostat screen go off and then come back on. Therefore, check the thermostat screen brightness and ensure the brightness is adjusted according to your own choice.

5. Failure to completely close the finance door

If the furnace door is opened or not completely closed, the thermostat will automatically go off and then come back on. Hence, check if the furnace door is completely closed and see if your problem is solved.

6. Incorrect wiring of the thermostat

Every thermostat has wires that need to be connected with the HVAC control unit. If the wires are incorrectly connected, the thermostat will go off. Ground yourself and try connecting the wires following the manufacturer’s instructions. If you can’t troubleshoot the wires, contact an electrician.

7. The thermostat fuse has been corroded

The thermostat fuse has been corroded

Most of the thermostats have internal fuses that regulate the power to be used by the thermometer. If the fuse has been blown out, your thermostat will be unable to function normally. Therefore, you will have to buy a new fuse for replacement.

8. Tripping of the thermostat circuit breaker

When the circuit breaker of your thermostat strips, the thermostat is switched off automatically, leaving a blank screen. First, to fix the problem, reboot the circuit breaker and check if the thermostat will turn on. If the problem persists, consult an electrician on how to replace the whole thermostat.

9. Dusty and dirty air filters

Dirt restricts smooth airflow making the AC turn off hence failing to supply power to the thermostat. Turning off the AC leaves the thermostat screen blank, and when the Ac turns on, it automatically turns on the thermostat. Always check your thermostat filter and clean all the dirt that has accumulated.

10. The whole thermostat is failing

The whole thermostat is failing
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If all the above fails to troubleshoot your thermostat, perhaps the whole thermostat has been damaged beyond repair. Most of the thermostats stay for ten years maximum. Confirm if your thermostat has stayed for a long period. Upgrade the thermostat by buying the latest version. Before buying a new thermostat, contact a licensed electrician to know if it can still be repaired.

Frequently asked questions:

  • How do you know that your thermostat has been damaged?

If your thermostat shows the following signs, then it has been damaged beyond repair.

a. After attempting all the troubleshooting methods, the thermostat fails to power, meaning that your thermostat only requires replacement. Buy a new thermostat of the latest version.

b. After turning on the AC but the thermostat doesn’t turn on. If your thermostat fails to turn on when the AC has been turned on and fixed, the thermostat is already damaged.

c. The thermostat does not respond to any of the commands.

  • Why is my thermostat not connecting with the furnace?

The following will reasons can make your thermostat not respond to the furnace.

      I. If dirt has accumulated either on the furnace or in the thermostat.

If your furnace is filled with a lot of dirt, the air flowing within the furnace will be hindered. The heat released is restricted within the furnace, making it overheat. Overheating automatically shutting the furnace to prevent it from blowing out. Once it has been shut down, the connection between the thermostat and the furnace will be restricted.

   II. The thermostat is not working correctly.

The furnace usually does not respond to a damaged or poorly installed thermostat. Check your thermostat installation, the wires if tightly connected, check the thermostat batteries if they need any replacement, and finally, inspect the thermostat fuse.

III. Inspect the power supply if it is turned on.

Check the AC if it is turned on and if not, try turning it on. Countercheck the cables if they have correctly installed and are tightly attached. If the power is turned off, the furnace will be unable to connect with the thermostat.


Monitoring your thermostat frequently ensures that your thermometer is in good condition. In case of any problems, you should be able to troubleshoot and solve them. The reasons and the steps of troubleshooting a thermometer that goes off and then comes back on are simple and easy to follow by experts and regular people. Moreover, it is important to keep your thermostat in a good state to continue functioning normally.

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