Honeywell Thermostat Wont Turn on Heat? this fix worked!

Honeywell Thermostat Wont Turn on Heat

Some of the common reasons why the Honeywell thermostat won’t turn on heat include faulty wiring, the thermostat having been installed in the wrong location, the furnace is off, weak thermostat batteries, broken temperature sensors, tripped circuit breaker, and incorrect configuration to the heating system.

Seeing that there are many reasons why your thermostat may fail to turn on heat, it is only fair to understand what to do. It all starts by diagnosing the problem and exploring potential fixes.

Why Won’t Honeywell Thermostat Turn on Heat?

1. Loose Wires

You can be sure that your thermostat will turn the heat on if the wires are loose. The same effect is experienced if the wires are not inserted in the right terminals.

Make sure to first check if the wires are inserted in the right terminals. It is important to ensure that the connection is done right.

Check for the matching marks on both the wires and terminals The good thing is that they are clearly marked so all you have to do is match the wires to the terminals.

Fix – Tighten Loose Wires and Match to Terminals

  1. Wear some protective gloves first before working on the wiring of your thermostat
  2. Check for the label on the wires and the terminals. Each wire has a letter labeled to match a corresponding terminal. Make sure to insert the wires in a matching terminal.
  3. It is advisable to hire a licensed technician to help with this if you are unsure or not confident enough to handle a DIY. They will handle the wire fixing and tighten any loose wires as well. You need to consider other options if this does not work to resolve the issue.

2. Wrong Thermostat Location

Thermostats are very sensitive which is why you need to find the right location for it. Be sure to place it away from places with constant air flow such as near the window or close to an air vent.

Note that whenever the air from outdoors blows over the thermostat it is possible that the heat will be stable. Take for example when the air outdoors is hot and the one inside the house isn’t.

Unfortunately, when the thermostat is close to the outdoor air it may confuse the situation and switch on the AC when it shouldn’t just because the air blowing close by is hot.

Fix – Place the Thermostats in an Appropriate Location

Always ensure that the thermostat is centrally placed within the house. It should be away from external influences especially those from windows or doors. The rule is to never place the thermostat close to an area with outdoor air influences.

3. Poor Battery for the Battery-Powered Thermostats

While not all thermostats are battery-powered, it is important that you keep up with the battery for those that are. At any given time, the Honeywell Thermostat needs to be at least 24 volts to function effectively.

This is easily obtained from a good battery. However, you need to keep paying attention to the battery power as it approaches its lifespan because the power will slacken. Every time the thermostat runs on a low voltage, it will not work properly.

In most cases, the thermostat will fail to achieve its function of turning the heat in your home. This is a failure on the part of the thermostat. Find out if the thermostat works with AAA or AA alkaline batteries.

Fix – Replace the Batteries

  1. Turn off the thermostat’s power from the circuit breaker. Simply move the switch to an off position.
  2. Next, remove the thermostat faceplate from the mounting plate. This will expose the battery compartment. In case there are hinges on the base plate, you need to unhinge them.
  3. Next, you need to remove the battery compartment from the base plate
  4. Next, remove the old batteries, and replace them with new ones
  5. Remount the battery compartment and push the faceplate back
  6. Finally, restart the device by switching on the thermostat via the circuit breaker

4. The Furnace may be Off

Remember that the thermostat needs and gets its heat from the furnace. It is therefore easy to see why it may not heat up if the furnace is switched off. The thermostat may not be in a position to pump up hot air if the furnace is off.

Check to be sure that the furnace was not accidentally switched off which is a common occurrence. For the electric furnace, check out for the double lever breaker. On the other hand, gas furnaces have single lever breakers.

Identifying the circuit breaker may be the biggest challenge especially if you are not too handy. You may have to switch on all the circuit breakers in the house as you try to identify the furnace circuit breaker.

Fix – Turn on the Furnace

  1. Locate the furnace circuit breaker. This may take a bit of trial and error especially if you are not familiar with such mechanical stuff
  2. Once you locate it, switch off the furnace circuit breaker. Also, test that the furnace is now on. In case it is still off, find the switch on the wall close to the furnace and switch it on.
  3. Finally, verify that the furnace door is closed. Note that some furnaces will not work in case the door remains open.

5. Poorly Configured Thermostats

In case the thermostat is just new, then it may not heat up as expected. This may be due to poor configuration settings. It is important for the thermostat to learn how the HVAC unit in your house works for it to be configured appropriately. To resolve such an issue, you only need to reconfigure the thermostat for it to be back to normal.

Fix – Configure your New Thermostat

  1. Start by pressing the button below System. You will notice a blank box appearing on the screen.
  2. Make sure to hold the empty box until the thermostat displays the thermostat’s model ID.
  3. Next, tap on this model ID.
  4. You should then choose an Installer Option. Note that the system will then request you to key in your Date Code. You should then locate your Date code which is found at the back of the thermostat. Note that your Honeywell thermostat should now display the correct installation settings.
  5. Next, press and hold the UP arrow and Fan button to start the process of changing your configuration settings.
  6. Your Honeywell thermostat will then display the function number 1 as well as the setting number 0. Function number 1 is meant for the heating and cooling systems. In contrast, the setting number in turn describes the HVAC system you are using in your home.
  7. Next, find the 5 setting number options located under the function number 1:
  8. You need to select 0 if you use a furnace with your AC (Note that 1 is for homes that only use heat pumps).
  9. You can then select 2 if you use a heater
  10. You should go for 3 if you use a heater with a fan and opt for 4 if you only want the thermostat to control your cooling systems.
  11. Finally, navigate through the setting numbers to find the option that describes your type of HVAC. After selecting the correct option, click Done and Exit the installation settings. At this point, the thermostat should turn on with so much ease.

6. The Thermostat circuit Breaker is Off

It is possible that s you waited for the thermostat to turn on the heat, chances are that the circuit breaker may have tripped. This will then cause the thermostat to switch off automatically.

Unfortunately, this can happen without your knowledge. In case you realize that the thermostat is not pumping up hot air into the house for a few minutes, you should check the thermostat and switch it on. If the thermostat is on, then consider checking the circuit breaker.

Fix – Turn on the Thermosts Circuit Breaker

  1. Confirm that the thermostat is first switched on. If it is then the problem may be in its circuit breaker
  2. Check to see if the circuit breaker tripped accidentally and switched itself off, cutting off the power supply to the thermostat.
  3. In case the circuit breaker is in the ON position then you need to switch it off as this is the only way power will flow.

Note that the Honeywell thermostat may refuse to heat up your house for various reasons. I have explored some of the most popular reasons this may happen. Even so, the issues may not be limited to this alone.

You need to learn basic troubleshooting tips. In case you are unsure about how to handle the repairs and fixes, it is best to have an HVAC expert examine the thermostat.

Brady Klinger-Meyers is an experienced writer and marketer with who currently writes for Robodens as well as other popular sites like MakeUseOf and Techzillo. At Robodens, he focuses on general smart home advice with his interest being accessories and gadgets. Read our Editorial Guidelines and Fact Checking process.


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