How to fix honeywell thermostat

By One Hour Heating & Air Conditioning

Honeywell thermostats are some of the most trusted and reliable thermostats on the market—but even the best technologies are subject to necessary reset and repair! If your home seems to be off a few degrees, if you’ve noticed your energy bill going up unexpectedly, or if your thermostat fails to trigger your heating and cooling system, it may require a reset.

What Is Wrong with My Honeywell Thermostat?

Resetting your thermostat can solve several issues, including:

  • Problems with your thermostat’s programming
  • Trouble connecting to your furnace or air conditioning unit
  • Inconsistent or inaccurate temperature readings

What Honeywell Thermostat Do I Have? 

To reset your thermostat, you’ll need to know the model. If you still have the product packaging or the thermostat ID card, your model number will be written on either of those items. If you don’t have that packaging on hand, you can remove your thermostat from the wall and locate the product number on the back of the wall plate.

Most thermostats can be gently lifted from the wall without tools. Pull evenly from either side of the thermostat. If it won’t come off, you may need to search online to find models based on their resemblance to your thermostat.

Resetting a Honeywell Thermostat

For battery-powered thermostats, there is a quick way to perform a thermostat reset. Here’s how:

  1. Power off the thermostat and remove the batteries.
  2. Put the batteries in the wrong way, with negative to positive and positive to negative.
  3. Wait ten seconds and put them back in the correct way.
  4. Your thermostat will be reset to factory settings. Be sure to reprogram your thermostat to your normal schedule.

Not all Honeywell thermostats use batteries. Those that don’t are hardwired to the home’s electrical system. For guidance to reset thermostats that don’t require batteries, look at this handy resource.

For more on how to replace Honeywell thermostat batteries, read on.

How to Replace the Batteries in a Honeywell Thermostat

If your unit does require batteries, replacing them is easy. If your screen looks dim or goes blank, don’t get worried until you replace the batteries. Here’s how to do it.

  1. Remove the faceplate of the thermostat. Most thermostats will simply pull off with even, firm pressure. Some models have small tabs on the top and bottom. A few seconds of inspection should make it clear whether your model has tabs.
  2. Remove the old batteries. Depending on your model, the unit may take AA or AAA batteries. Look at the batteries you are replacing to confirm the right size.
  3. Install the new batteries into the battery compartment.
  4. Put the faceplate back onto the backplate. Once it is reconnected, the thermostat display should turn back on. Take a moment to confirm that any programmed settings are still stored correctly by selecting the Menu or Program key, depending on your Honeywell model.

If the thermostat display does not turn back on, contact One Hour for expert thermostat services.

How to Unlock a Honeywell Thermostat 

Like a factory reset, the steps for unlocking your thermostat depend on which Honeywell model you own. For most Honeywell models, however, the process is similar. Most users will need to lock or unlock their thermostat to limit how many family members can control programming or adjust the temperature.

  1. Press the Center or Menu button and enter 1234.
  2. If you are setting up your thermostat for the first time, you’ll be able to set a passcode. Save this number somewhere you won’t lose it, such as on your phone.
  3. Select the Lock option to restrict access to changing temperatures or reprogramming the unit.

I Lost the Passcode for My Honeywell Thermostat 

Don’t worry, there’s a workaround for this!

  1. Repeat the first step of the instructions above. If you get an error or incorrect warning when you input the number 1234, carry on with the steps below.
  2. Remove the thermostat from the base plate. On the back of the thermostat, you’ll find a four-digit date code.
  3. Add 1234 to the date code. For example, if the date code is 1420, then add 1420 + 1234. The new passcode would be 2654.
  4. Enter in the new passcode from the Menu option on the thermostat. Then you will be able to reset your passcode.

Troubleshooting Honeywell Thermostats 

If you tried a reset, replacing the batteries, or unlocking your thermostat to no avail, it’s time to call in the professionals. Trust One Hour to help with all your heating and cooling needs with fast, experienced technicians that can fix HVAC problems both big and small. Call (800) 893-3523 or request an appointment online to get started.

Display Screen is Blank

Is your Honeywell thermostat not working, or does the display screen appear blank? This is one of the more common thermostat problems. If this issue happens with a programmable thermostat, try replacing the batteries. If that doesn’t fix things, there could be a problem with your wiring.

The next step is to check the power source. On the indoor unit, make sure the switch is in the “up” position. Another tip is to ensure all doors and panels are closed properly on your unit. Closely examine both your indoor and outdoor systems to see if any of these compartments are left open. Close them if that’s the case, and make sure they’re tight. If one of these panels isn't secure, it could trigger a safety switch that powers off your unit.

A common mistake that homeowners make is assuming their thermostat is broken and must be replaced. Although that’s true in some cases, a blank screen rarely ever indicates a broken thermostat.

Problem Inside Thermostat

On some occasions, a Honeywell thermostat not working could mean the inside of the equipment has an issue. To troubleshoot this, head over to your electrical breaker box and turn off the power that runs to your thermostat. This is to prevent electrical shock or cause any issues when looking inside. Then, carefully remove the cover and examine the wiring inside your thermostat. Check to make sure nothing is detached or broken. Also, ensure everything looks clean. If you don’t find any problems, the issue could lie with your HVAC system. If you have an old and aging thermostat, replacing it is another option that may work.

Indoor Temp Doesn’t Match Thermostat Reading

Another one of the common Honeywell thermostat problems is a thermostat that reads a temp that doesn’t match the actual temperature in the room. For example, your thermostat may read 80 degrees when your house feels more like 60 degrees. In this case, you could have a broken or malfunctioning temperature sensor. All thermostats have these sensors; it helps the device understand and maintain indoor temps. So when these break, your thermostat may have no idea what temperature it actually is in your home.

To solve this issue, use a standard thermometer to measure the actual temperature near your thermostat. If these numbers don’t match up, a broken sensor could be the problem. You can either replace the sensor or buy a whole new thermostat. Speak with a local HVAC professional to help choose the best option for your needs.

Test the Settings

Is your Honeywell thermostat not cooling? If you suspect a problem with your system, test the settings to ensure everything is working as it should. If you have an analog thermostat, you should have an option for heat, cool, or off. You probably also have a switch to change your fan settings to auto or off. The easiest test for your thermostat is to switch to heat and crank the temperature up. If your heater turns on, your heating system is working. You’ll then want to do the same thing for your air conditioner. Move the switch to cool and crank down the temp. If your unit powers on, you're in luck.

Honeywell Thermostat Not Cooling

Is your thermostat set to cool, but your air conditioner won’t kick on? If you signed up for a saver switch, your utility company may be locking you out of the system. If not, try the following Honeywell thermostat troubleshooting tips:

  1. Ensure the thermostat is in the cool setting and has a temperature that’s set lower than the actual temperature in the room. If it’s set at or above this number, your air conditioner won’t power on.

  2. Check your thermostat display screen to see if the cooling mode is activated. It should say “cool on” or have a snowflake icon. If these words or icon are flashing, your thermostat is in delay mode. This will last about five minutes. This delay is intended to prevent your system from short cycling.

  3. If your thermostat says it’s in cooling mode, make sure the door to your furnace

    is completely closed. Also, make sure the power switch to your furnace is turned on. 

  4. Lastly, ensure the furnace circuit breaker switches are turned on.

If your thermostat still doesn’t power up your cooling system, and it has worked in the past, contact an HVAC professional for assistance.

If you just had your system installed, or if this is the first time you’re using your thermostat since buying new equipment, try the following:

  1. Make sure the wiring matches up correctly, just how it was used with your last thermostat. As some models connect differently than others, be sure to follow the installation guide that came with your thermostat. 

  2. Ensure the thermostat has been configured properly with your HVAC system. Look for the Installation and User manuals for your products and make sure the thermostat is configured correctly for your specific system type.

Still Having Issues? Call A Professional HVAC Contractor

Honeywell thermostat won't turn on heat? Want to learn how to set Honeywell thermostat? Whether you have a new system or you’re experiencing issues with your existing unit, calling a professional HVAC technician is a smart decision. They can set up everything correctly and show you how to use your thermostat.

Especially with the modern HVAC systems and thermostats used today, this equipment can get confusing. Calling an HVAC professional doesn’t only provide peace of mind, but it can also help prevent future system issues.

Dealing with these problems can be stressful. We hope these Honeywell thermostat troubleshooting tips have helped!