Honeywell thermostat not working

Honeywell thermostat not working. A Honeywell thermostat can make your home comfortable by maintaining the temperature.

Everything will be okay till your Honeywell thermostat work properly. But nobody can take the lifetime guarantee of an appliance.

Same as other appliances, your thermostat may start malfunctioning. Maybe it stops working efficiently, or it stops turning ON.

If there is the same situation or problem with your appliance, and you don’t know what the problem is.

Then you may follow these instructions to troubleshoot your Honeywell thermostat problems.

One more thing that we want to add is that no doubt this article is about Honeywell thermostat, but if you have another brand, this information can also help you.

Because mostly thermostats share common problems, and by reading these guidelines, you may be able to understand the issue of your device.

Honeywell thermostat not working

Troubleshooting Honeywell Thermostats

Here, we’ll discuss why your thermostat is not working, what things you may do to diagnose the issue and what steps you should follow to repair the problem.

Battery Failure

battery failure

The most apparent reason that may stop your Honeywell thermostats from working properly is dead batteries or batteries are not placed in the correct position.

If your thermostat contains a battery and stops working, you need to check the battery inside your Honeywell thermostat.

We don’t want you to go in more depth because you may fix the problem with a small solution initially.

So, you can need to access your thermostat’s battery.

So, firstly, you need to turn OFF the circuit breakers, and then you need to turn OFF the power switch of your Honeywell thermostats.

From the wall, the plate detaches the thermostat carefully.

It would be best if you were careful while detaching it because each model has a different way of detaching the thermostat from the wall plate.

Please don’t break it while using an inauthentic way.

Now, check the batteries are inserted correctly in their position.

If not, then you need to align them. Secondly, you must check if your thermostat uses old or dead batteries.

You may also check the working by inserting the fresh set of batteries in the thermostat or use a better tester to examine the old ones.

Electric Power Failure

electric power failure

If your thermostat is not working after inserting the new batteries, you may check if there is a problem with the electric power.

As you know, electric appliances require electricity to fulfill their need to work smoothly.

So, if a circuit fails to transfer the required voltage, it may cause improper working of your thermostat.

To troubleshoot this issue, you need to check the wires to see if there is a crack or if the wire is damaged, disturbing the electricity flow.

You may examine the wires physically and use a multimeter to measure the electrical voltage.

If you feel any problem with the wires stopping your thermostat from working, you need to replace the wires.

Turn off the power as a safety measure. After fixing the issue, you may turn it On the back. Check whether your thermostat started working or not.

Wiring Inside the Unit

wiring inside the unit

You need to examine the loose wiring of your smart thermostats.

If your Honeywell thermostat is still not working and you have checked the battery and electric flow, then there might be a problem inside your device.

You need to gain access to the unit for an overview to diagnose the issue.

Honeywell thermostat permanent hold

But before tackling your thermostats, you need to turn OFF the power source from the electrical breaker box and your Honeywell thermostat.

Then, remove the cover of your thermostat unit. The next step is to examine the wiring inside the unit.

If you see any loose wire connection or breakage, you need to repair it.

You may also check that the inside of the unit is clean.

If you see no connectivity problems, you must continue diagnosing the problem for not working your Honeywell thermostat.

Thermostats Blank Screen

thermostats blank screen

A blank display screen is one of the common thermostat problems.

If you are facing a problem in which the digital screens remain black or only show blinking digits.

Then there are a few reasons that disturb your thermostat’s efficiency.

To troubleshoot the blank digital screen, you must check the following few tips.

  • Batteries: If your unit has a blank screen or is just blinking the digits, you need to check whether the batteries are dead or not.
  • Loose Wire Connection: The following reason for the blank screen is a loose wire connection inside your thermostat unit. You need to access the unit to take an overview of wires connections.
  • Access Door Open: Open-air handler doors/panels or furnace doors of the HVAC system activate the safety switch. To resolve this issue, ensure the furnace door is closed properly.
  • Tripped Circuit Breaker: Tripped circuit breaker could be a reason for a blank display screen. Ensure that the HVAC system’s own circuit breaker switch is in the correct position.

Malfunctioning Temperature Sensor

malfunctioning temperature sensor

A broken sensor may create trouble for you by not maintaining the temperature.

Honeywell thermostat recovery mode

According to the Honeywell thermostat information, the display screen may show something else, digits of temperature, and you feel it is too cold or too hot.

This situation happens in the case when your unit has a defective sensor.

When the sensor got defective, it lost the sense of suspecting temperature.

If you want to ensure that the sensor is working fine or not, you need to follow a two-minute process, in which a thermometer is required as a tool.

It would be best if you examined the temperature by using the thermometer.

Note the temperature from the thermometer and then match it with the temperature of the thermostat display screen.

If it doesn’t match, then it’ll be a smart decision to buy a new thermostat.

Air conditioner Failure

air conditioner failure

The thermostat helps us feel comfortable in our houses, offices, or any place where we spend most of the time.

If it’s winter, it provides a warm temperature, and in summer, you may enjoy a fresh, relaxed environment.

But what will happen if it stops air conditioning on a hot summer day. Don’t panic; follow these instructions to solve your issue.

Firstly, you need to check that thermostat is turned On and ensure that thermostat is set on the Cool settings.

Secondly, you must check that all the furnace access doors are completely closed.

But if your thermostat is still not cooling, that indicates that your thermostat is in delay mode.

You may notice a flashing code on the thermostat display screen.

Don’t worry. Delay mode takes 5 minutes to start your air conditioner usually.

If you are still facing any problems, you need to proceed next step of troubleshooting your thermostat.

HVAC System Failure

hvac system failure

Whenever you suspect that your Honeywell thermostat is not working correctly, it means if you have switched it on heat mode, it starts blowing hot temperatures.

It fetches that your HVAC unit is not working correctly.

One more thing that you need to check is whether the handler doors or furnace cabinet doors are fully closed if they are open, then HVAC won’t work correctly.

The following reason that is a sign of defective HVAC is that your thermostat does not respond in any way.

You can diagnose it by following these instructions.

Firstly, you must switch your thermostat to Cool or Heat mode according to your choice.

Then you need to set the heating system highest or lowest besides the actual temperature so that you can easily suspect the issue.

You may reset the circuit breaker to set Honeywell thermostat issue. You need to give five minutes for the compressor to turn ON when the HVAC unit turns on.

Installation of HVAC System

The first thing that wants your attention while installing the thermostat is, don’t install it in warm places, e.g., near the kitchen, near a firestone, or the spot where your thermostat may face direct sunlight.

Installation of your HVAC affects on thermostat temperature.

If you have an aging thermostat, you may know that older thermostats depend on a mercury switch.

So, if you want your system to work properly, then make sure that your thermostat is installed on a proper level.

Honeywell thermostat flashing cool on

Because if it is not leveled, your mercury switch may stop your thermostat from accurate temperature.

To troubleshoot this issue, you are required a level and a screwdriver to maintain your thermostat level.

Carefully remove the thermostat, align it with a level, and ensure that it does not bend at one side, even a few degrees. If the problem cannot be solved, then contact support.


We hope that these instructions can solve your problem with Honeywell thermostats.

If you follow all the guidance with concentration, there are high chances of resolving the issue of a smart thermostat, digital thermostat, programmable thermostat, or analog Honeywell thermostat.

If you are feeling nervous you may contact a professional.

Because we don’t want that you may create other problems with your thermostat while Honeywell thermostat troubleshooting.