Honeywell Thermostat Not Working (We Tried ALL Fixes!)

Honeywell thermostats range anywhere from smart thermostats to basic non-programable thermostats. They are easy to use and work well in homes or apartments. Unfortunately, technology can only take us so far and sometimes fail us. When your Honeywell thermostat is not working it may be frustrating. 

There are several ways to fix a Honeywell Thermostat. Start by troubleshooting the thermostat. Check error codes. Check the settings. Check your wifi. Check for loose or broken wires. Check the room temperature. When issues can’t be fixed by troubleshooting move on to more intense fixes. Check for a clogged HVAC or call a professional for help.

Damage Honeywell Thermostat

When your Honeywell thermostat is not working you will need to try to troubleshoot or fix it. Below are all of the ways you can try to fix your thermostat. After you review this article you will have expert knowledge on how to fix a thermostat. 

How To Fix Honeywell Thermostat That is Not Working 

To fix a Honeywell thermostat you need to either troubleshoot, clean, repair or replace parts of the thermostat. You need to know your limits when repairing or replacing parts of your thermostat or HVAC system. If you have never repaired something you should call a professional, as the skill level for repairs and replacements is high.

The tools to fix a Honeywell Thermostat or replace parts include, but are not limited to: batteries, screwdrivers, pliers, socket wrenches, wire cutters, electric tape, and adjustable wrenches. To replace or repair you should have some of these tools on hand. If you do not, you should stick to cleaning or troubleshooting.

Test the Honeywell Thermostat Settings

To test the Honeywell thermostat settings you need to take a look at the display on the thermostat. Test the thermostat by setting it to on and turning the heat above the temperature in the room. If the heating system turns on then it is working.

You’ll want to test the air conditioner as well. Do this by keeping the thermostat on and setting the temperature lower than the rooms. If you hear the air conditioner turn on then it is working just fine.

Testing a thermostat does not take long and will tell you if the heater and air conditioner are working properly. If one of the two is not working, you will have to look at more significant issues.

Clean the Inside of the Unit

There are several easy ways to clean the inside of the unit. You should keep up with regular maintenance on your HVAC system so that your thermostat will work properly. What you can do first is replace the filter which should be replaced every 3 months. Use a vacuum to clear any debris.

More simple maintenance includes making sure there are no plants growing too close to the A/C unit.

Check for leaks around the piping. Leaks cause many problems and you should check for them if your thermostat is not working. Finally, you should cover your A/C unit in the winter to keep it safe.

Display Screen Not Working

When the Honeywell thermostat display screen is black there are several ways to check and fix the issues. The first issue you need to check is that the batteries are not dead or that the Honeywell is charged. Dead batteries will cause a black screen.

Another reason the display screen could be black is because of a tripped circuit. Check your breaker system and make sure everything is running correctly. 

Lastly, if the HVAC systems door is not completely closed the thermostat may be black. This is a safety precaution so check to ensure the HVAC system door is closed.

Heat Won’t Turn On

To fix a thermostat that the heat won’t turn on you should start by testing the settings. Make sure that the temperature you want it to heat to is higher than the one in the room.

Check to see that you have it set to heat. Check to see if the thermostat is level. If your setting is correct try to restart the thermostat.

If your heat won’t turn on after checking the settings of your thermostat then you should take steps to clean the filter and check anywhere for leaks. Finding the main issue when your heat won’t turn on may be a sign to call a professional so you don’t waste any time.

Temperatures Don’t Match

When your thermostat is reading a different temperature than what it actually feels like you have a sensor issue. The sensor is likely broken and needs to be replaced. To be sure you should  measure the air next to your thermostat with a thermometer.

A sensor is difficult to replace so you may need to call a professional. Another option would be buying a whole new thermostat altogether. Buying a new thermostat would be a cheaper option than calling a professional. It would also be quicker than trying to figure out and replace the sensor.

The Display is Active But Unresponsive

Check the settings, wires, and room temperature if the display is not responsive. The thermostat may have a sensory issue. The thermostat’s sensory could be broken or malfunctioning. This would mean the temperatures don’t match but there are other potential issues as well.

The setting may be a reason why the display is active but unresponsive. If the date and time settings are off this could be the root of the issue.

Along with issues with loose wires and wrong jumper settings on the HVAC system. If you check all of these potential issues and the display is still unresponsive you may need a new thermostat. 

Check Your Wifi Connections

Wifi connections can be another reason why your Honeywell thermostat won’t work. Smart thermostats require wifi to function.

There is a wifi symbol in the top right corner of the thermostat. If there is a line going through it it is not connected. To fix this there are several ways that you can reset your wifi and thermostat

The first way to fix your thermostat’s wifi connection is by taking it off the face plate for 20 seconds and then reattaching it. The thermostat should reconnect. If it does not then you should head over to your router or check your internet provider’s connection on your phone.

To reset the whole wifi system you should unplug the power from the router for about a minute and then plug it back in. The system will reboot and the thermostat will have wifi. If the wifi is still down you should check for potential outages or contact your internet provider.

Check That Your Wires Are Compatible

Honeywell thermostat requires wires that need to be compatible to charge it. Either a C wire or a USB wire. 

A C wire will be connected to the thermostat so that it has a constant charge. Some Honeywell thermostats don’t have a C wire port so you need an adapter. If you have the wrong wire in the thermostat will not be charging.

If you use a USB to charge the thermostat make sure you are charging it using the right one. There are several different types of USB chargers. Check the institutions of your Honeywell thermostat manual.

Check The HVAC For Clogs

Checking for an HVAC clog is an intense process that requires expert knowledge. To check for a clog you will need a pipe-cleaning brush. PVC pipe cutter, a premade rubber coupler with clamps, and a shock vac. 

Once you have those tools you will be able to check the HVAC for clogs. Clogs happen within the pipes and you have to sometimes take them off to get the clog. 

The first thing you can do is find the drain line outside and use a shock vac to suck the water and potentially the clog out. Otherwise, you will need to go to the HVAC and take some pipes off to check them. That may call for a professional’s help.

When To Call a Professional

There are many situations that require a professional when your thermostat is not working.

Such situations can range from:

  • Having to take a look at your HVAC system
  • Cleaning out pipes if you do not have the right tools. 
  • Taking a look at the electrical panel. 
  • Fixing wires
  • Replacing a thermostat
  • Replacing pipes or wires in the HVAC system
  • Connecting a C wire
  • Cleaning the outside unit

Calling a professional is one of the hardest parts of when your thermostat is not working. We would all love to be able to fix every problem but we can’t always.

Finding the right professional may be challenging as well. Take a look at reviews to find the best possible professional. You can also call and try to get quotes for pricing.

You should be aware of safety concerns if you are fixing your thermostat. You can be shocked, cause a fire, or break your HVAC system. The biggest safety precaution you can take is turning off the power. This way you will not get shocked or accidentally start a fire.

However, you should also know your limit. If you don’t have the means to fix a thermostat there is no shame in calling a professional. They are the experts and they are there to help you.

Troubleshooting a Honeywell Analog Thermostat

An analog thermostat is a basic thermostat. It is not digital and does not require wifi or connection to an app on your phone. These thermostats are the least expensive but not always the most reliable. 

A digital thermostat is a smart thermostat. These are more expensive but work better. The temperatures are more accurate and they have more features. These features include an eco mode, controlling the thermostat from your phone, to explaining what is wrong with the thermostat.

If you have a Honeywell analog thermostat there are only a few ways to troubleshoot it. Troubleshooting includes looking at the settings and wires. 

You need to check the cooling and heating. Set it to cool and put it at a low temperature. Then set it to heat and put it at a hot temperature. Wait 5 minutes after doing both to see if the systems are working. 

If one of those or both is not working take off the cover of the thermostat. Look to see if any wires are loose or broken. If none of those are the issues then you may need to call for help or look at the HVAC system itself.

Troubleshooting a Honeywell Smart Thermostat

Troubleshooting a Honeywell Smart Thermostat requires the same steps as an analog thermostat and a programable thermostat. Since it is a smart thermostat it will be easier to tell what is wrong. 

The smart thermostat will display error codes that will tell you what is wrong. These are the codes you may encounter:

Error codes that are common but may need professionals help are:

  • 164 – The heat pump needs to be serviced
  • 168 – There is a wifi error and you should check the wifi
  • 170 – The internal memory has an issue
  • 173 – The thermostat temperature sensor has an issue
  • 177 – There is an indoor temperature sensor error
  • 178 – The outdoor temperature sensor has an issue

Error codes you should be able to fix on your own:

  • 171 – Set a date and time to schedule your thermostat
  • 181/182 – You need to replace the air filter
  • 183 – You need to clean the humidifier tank and add put in a new filter
  • 185 – You need to get a new dehumidifier filter and replace the old one
  • 388 – You need to register online for remote access and the exterior temperature
  • 399 – There is no internet
  • 400 – There is no wifi signal
  • 508 – The wifi has disconnected

Troubleshooting a Honeywell Programmable Thermostat

You can troubleshoot a Honeywell programable thermostat in several ways. 

When the display is black there are four ways to troubleshoot the thermostat.

  1. Change the batteries or charge the thermostat
  2. Check to see if your circuit breaker is tripped
  3. Make sure all panel doors are closed on the inside unit
  4. Check the power for the furnace and A/C. The switch that is next to the indoor unit should be flipped up.

When the thermostat should be on but no heat or A/C is coming out.

  1. Check the settings. Make sure the date and time are correct
  2. Check to see if the temperature set is either higher or lower than the temperature in the room.
  3. Check the wires. Remove the cover and see if any wires are loose or broken
  4. Check the jumper settings.
    • Electric furnaces will have it switched to HE
    • Gas furnaces will have it switched to HG
  5. Lastly, try the troubleshooting methods of the analog thermostat

If you follow all of these steps and the thermostat is still not working properly you should call a professional. You can always take a closer look at the furnace or HVAC system before you do.


There are various ways to fix a Honeywell thermostat that is not working. You should try to troubleshoot before you take any of the more difficult steps. Know your limits and call a professional if you need to.

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