Honeywell Thermostat Not Working? 10 Ways To Fix It Now

A functional thermostat is vital for maintaining comfort and energy efficiency in our homes.

It serves as the control center for our heating and cooling systems, allowing us to regulate temperatures and create a comfortable living environment, regardless of outside temperature.

Is your Honeywell thermostat blinking or showing a blank screen?  Don’t call the repair guy just yet.

Whether it’s an older analog model or one of the newer Wi-Fi-enabled smart Honeywell pro series with internet connectivity and remote access capabilities, many common Honeywell thermostat problems can be fixed with some easy DIY troubleshooting.

In this article, you’ll learn how to get the digital screen to work again if it has gone blank, get the heat or AC back on if the system is no longer responding, and many more.

So, hang tight, and let’s breathe new life into that lackluster Honeywell.

Why is the Honeywell Thermostat Not Working?

There are several common reasons why your Honeywell thermostat may stop working properly:

Dead or Low Batteries

Depleted batteries or batteries showing a low battery warning are a common source of thermostat failures.

Routinely replacing old or low batteries with fresh ones can fix blank screens and unresponsive thermostats. Make sure batteries are oriented correctly.

Loose Wire Connections

Loose wiring causing incorrect or disrupted connections can lead to thermostat malfunctions.

Inspecting wire terminals and properly reconnecting loose wires to assigned terminals will resolve many issues. Also, check for damaged wires needing replacement.

Related: How Do I Wire My Thermostat

Faulty Thermostat 

It’s a no-brainer that problems with the thermostat’s internal components such as the control boards, sensors, and screens, can to failures.

These faults in thermostats are not common to a particular type of thermostat. Rather, they can occur in various types of thermostats including analog models, programmable thermostats, and smart Wi-Fi-enabled thermostats.

Signs of a faulty thermostat include Honeywell thermostat display not working, flashing screens, inaccurate readings, wi-fi radio error icon, buttons not working, and different kinds of error codes.

There are also chances of the thermostat temperature sensor error occurring. Unlike most problems in this guide, this one requires expert support.

Incorrect Settings 

If you input the wrong settings for mode, temperature, fan speed, programming schedule, etc., it can make your functional thermostat appear faulty.

So, if your thermostat is not reaching the desired temperature, double-check all settings per user manual and adjust what needs adjusting.

Power Disruptions

tripped breaker

Power issues due to tripped breakers, safety switches being off, electrical faults in wiring, loose C wire connections (for smart models), AC power disruptions, etc. can cause blank screens and unresponsiveness, leading to difficulties in getting the heat on.

Restoring proper power flow by checking and resetting the safety switch resolves many no-power problems, including issues related to the Wi-Fi signal.

Furnace/AC Unit Malfunctions

Underlying issues with the furnace cabinet or Air Conditioner unit itself manifest as a thermostat problem.

For example, the Honeywell thermostat AC not working or the Honeywell thermostat heat not working despite the thermostat being set to cool or heat mode signifies a heating or air conditioning malfunction, which could be caused by an outdoor temperature sensor error.

Units not turning on despite correct thermostat settings indicate an HVAC malfunction requiring professional maintenance and repairs.

Clogged Air Filters 

dirty air filter

Clogged filters restricting airflow prevent the HVAC system from responding properly to thermostat commands.

Replacing a dirty air filter with a new filter or cleaning dirty air filters removes obstructions and allows for normal thermostat function.

Thermostat Location

Incorrect location can lead to inaccurate temperature readings. Relocating the thermostat away from direct sunlight, drafts, vents, etc. provides proper ambient temperature data.


In low ambient temperatures, the icing up of the AC coils prevents the thermostat from controlling temperature and humidity properly. Maintaining adequate room temperatures prevents freezing issues.

Short Cycling 

Frequent on/off cycling due to improper HVAC system sizing causes insufficient heating or cooling. Properly sized systems with a clean and fresh filter prevent short cycling issues.

Stuck Relays

Mechanical relays in the thermostat getting stuck can prevent operation. Exercise relays during routine maintenance help prevent sticking.

Jumper Settings  

Incorrect jumper configuration for the system type (conventional, heat pump, etc.) can cause heating/cooling failures. Verifying jumper settings as per the wiring diagram is important.

Programming Schedule Issues

Wrong temperature and time settings for the programmed schedule make the thermostat turn on/off, and heat/cool incorrectly. Checking schedule settings resolves such issues.

What To Do If Honeywell Thermostat Is Not Working

If your Honeywell thermostat is not working properly, there are several troubleshooting steps you can take to diagnose and resolve common issues.

Before attempting any of the DIY troubleshooting or repairs in this guide, be sure to take these important safety precautions:

  • Switch off the power supply to the thermostat and HVAC system at the circuit breaker to avoid electric shock hazards.
  • Use insulated tools when working with electrical connections and wiring. Never touch bare wires with wet hands or while standing on wet surfaces.
  • Wear safety goggles and gloves when cleaning air filters or AC coils.

1. Replace Batteries

Replacing batteries is one of the simplest fixes you’ll ever perform. Begin by removing the old, depleted batteries. Make sure you have a fresh pair of new batteries on hand.

After removing the old batteries, carefully insert the new ones. However, keep in mind the order in which you removed the old batteries so that you may place the new ones in the correct order.

2. Check Wire Connections  

honeywell thermostat not working

Wiring connections can occasionally cause your Honeywell thermostat to malfunction. Let’s take it apart and look at those cords!

  • Begin by gently removing the thermostat body from the wall plate; look for little tabs on the sides or bottom that allow it to release easily. Then, take out a flashlight and shine it on the interior electrical connections.
  • Inspect each wire to ensure that the termination screws or clamps are securely fastened. Gently pull on them; if properly attached, they should not budge. Check the wires for damaged or frayed places. Wires that are damaged must be replaced.
  • Finally, take a peek at the wiring diagram in your model’s manual to verify all wires are matched to the proper terminals. You’ll typically see letters like W, Y, G, R.

3. Reset the Thermostat

Resetting the thermostat can clear up software errors and glitches causing malfunctions. It erases all customized settings and restores factory defaults.

To reset your thermostat, do the following:

  • Depending on your model, you’ll most likely have to use your device’s touchscreen interface or physical buttons to carry out the reset. Common buttons you’ll likely use include “Menu,” “Back Arrow,” and “Hold.”
  • If you use a touchscreen model, press the “Menu” button to access the settings. On settings, scroll through the menu to find the “Reset” or “Factory Reset” option. Once you find it, select it.
  • Now, your thermostat should prompt you to input your password to confirm the reset. Input your correct password now.
  • Once you have confirmed the reset, press and hold the “Confirm” or “Reset” button to initiate the reset process.
  • You are almost there. Once the reset is complete, your Honeywell thermostat will return to its factory settings. And now, all you have to do is reconfigure your preferred settings which includes the date, time, temperature settings and Wi-Fi network.

Quick Hack. If your thermostat has battery’s, you can quickly reset it by removing the battery’s and intentionally placing them in the wrong direction.  Wait a minute, then reinstall the batteries in the correct position.  This will reset the thermostat.

It’s that simple! Your thermostat is now reset to factory conditions, which often resolves glitches causing operation issues. Still finding it difficult? Refer to the owner’s manual for the specific steps to reset.

Related: Quick Guide to Reset Any Honeywell Thermostat Model

4. Adjust Thermostat Settings

Make sure all the settings, on your thermostat are adjusted correctly according to your preferences. This includes the heating/cooling mode, temperature, fan speed, programming schedule and even the delay mode.

To adjust your thermostat settings, follow these steps;

  • Go to the home screen and press either the “Menu” or “Settings” button to enter programming mode.
  • Use the arrow keys to access the mode field and make sure its set properly to either “Cool” or “Heat,” depending on your needs.
  • Next adjust the temperature field incrementally by 2 degrees higher or lower than the current room temperature in order to activate heating/cooling.
  • Scroll down to the fan control field. Select “Auto” so that the system can automatically control the fan speed as needed.
  • Review all schedules. Set date and time options according to your comfort preferences. Be sure to check for any issues with your programs and correct them if necessary.

5. Check Power Supply 

If you’re experiencing power issues one potential solution is to reset the circuit breakers.

Here’s how you can reset the circuit breakers, in battery powered models;

  • Locate the circuit breaker for supplying power to your thermostat and HVAC system.
  • To reset it switch it completely to the “Off” position for 30 seconds. Then switch it back, to the “On” position.
  • Once power is restored check your thermostat screen for any indications of power problems or error messages.

For hardwired models, ensure the C wire is securely connected, and the furnace power switch is on.

You can do that, by doing the following:

  • Remove the thermostat body and verify the thick gauge wire is securely attached to the “C” terminal.
  • Check the voltage between the “R” and “C” terminals with a multimeter. Nominal 24VAC should be present if powered correctly.

If after inspection, you suspect a wiring fault, call an electrician immediately. Lack of power causes most blank screen and unresponsiveness issues.

6. Verify HVAC Unit Functioning 

dirty ac

Malfunctions in the furnace or AC unit can manifest as thermostat failures. You can verify if your HVAC unit is functioning properly by doing the following:

  • Visually inspect the furnace blower motor and listen as the thermostat calls for fan operation. If the blower does not activate, try manually starting the fan.
  • For A/C units, go outside and observe if the condenser spins up when cooling starts. Listen for any unusual sounds from the compressor.
  • Remove debris-like leaves from around the condenser unit to allow proper airflow. Keep plants and bushes at least 2 feet away.
  • When heating is called for, monitor the furnace flame ignition through the viewing window. It should light smoothly without delays.
  • Have an HVAC technician inspect your evaporator coils, refrigerant levels, blower motors, and other components during annual maintenance.

7. Relocate Thermostat

If your thermostat location is near vents, direct sunlight, or other sources of temperature fluctuations, inaccurate readings can occur.

If you think that the location of your thermostat is the reason behind your device not working, do the following:

  • First determine if your thermostat location is susceptible to radiant heat, cold drafts, dead air spots, or other temperature influences that may impact reading accuracy.
  • Avoid installing near windows, doors, air vents, skylights, heat-generating appliances, exterior walls etc. which distort temperature.
  • Ideal placement is around 5 feet above the floor on an interior wall in a frequently occupied room like a hallway.
  • Turn off the power to the thermostat before relocation. Take a photograph of the wire terminal connections for reference.
  • Detach the wires by loosening the terminal screws. Coil and bundle the wires to prevent tangling during reinstallation.
  • Mount the new thermostat base plate at the desired spot using drywall anchors if needed. Pull wires through the central hole.
  • Match and reconnect wires to their assigned terminals according to previous thermostat wiring and photo.
  • Reattach the thermostat body and turn the power back on once the wires are secure. Test heating/cooling operation.

Doing this should fix thermostat issues caused by improper location.

8. Update Thermostat Software/Firmware

For programmable and smart Wi-Fi-enabled models with internet capabilities, it’s important to register your thermostat on the manufacturer’s website to receive important software updates.

These updates not only fix bugs and glitches but also introduce new features and improvements to the thermostat technology. Refer to your thermostat manual for steps to check the version and perform updates for your wi-fi-enabled device.

Regularly check for and install available updates to ensure that your 5-2-day programming schedule functions properly and takes advantage of new features.

Related: How to Unlock Honeywell Thermostat

9. Test Components Individually

multimeter checking thermostat

When dealing with thermostats testing individual components such as sensors, circuit boards, screens, etc. can be helpful in diagnosing the issue.

To test the parts of your thermostat, follow these steps:

  • Begin by removing the thermostat cover to gain access to temperature, humidity and other sensors.
  • Consult the troubleshooting guide for information on how each component should function and guidance on how to test them.
  • Pay attention to any damage like cracked screens or water corrosion; if you come across any of these issues it indicates a need for replacement.
  • Employ tools like multimeters to check circuits, resistance levels and signals in order to identify faults.
  • Even if testing shows that a sensor is functioning correctly, but you notice condensation or incorrect temperature/humidity readings persisting it is likely that there are underlying sensor issues.

10. Professional Replacement

If your troubleshooting efforts have not resolved the problems, you’re facing with your thermostat hardware it may be necessary to seek assistance, for a replacement.

Get in touch with an HVAC technician to get an assessment and have them install a new thermostat for you.

Final Thoughts

While Honeywell thermostats are generally reliable, you can take proactive steps to prevent common issues leading to malfunctions.  ​​​​Issues like blank screens, unresponsive buttons, and heating/cooling failures cause discomfort. 

The inability to adjust your thermostat also leads to inflated utility bills as it runs inefficiently. In worst cases, malfunctions can pose safety risks from short circuits and overheating.

To avoid these problems, it is important to routinely troubleshoot issues and perform preventive maintenance. Simple steps like replacing batteries, checking wire connections, cleaning air filters, and verifying settings go a long way. 

By following this troubleshooting guide provided, you can diagnose and resolve the most common Honeywell thermostat faults yourself without professional help. This restores smooth and efficient climate control.

Being proactive also averts many problems down the road. Investing a little time upfront prevents inconvenient and costly breakdowns during extreme weather when you need your thermostat the most.

So don’t ignore a misbehaving Honeywell thermostat. With this handy guide, you can get it functioning properly again and maintain comfort and savings.

Related Article: Honeywell Thermostat Cool on Blinking

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