Honeywell Thermostat Heat Not Working on Auto

9 Min Read
Honeywell Thermostat Heat Not Working on Auto

Is your Honeywell Thermostat Heat Not Working automatically? There could be a variety of reasons why your Honeywell thermostat isn’t turning on the heat.

The major reasons why your Honeywell thermostat won’t turn on the heat are that the furnace isn’t switched on, the furnace door isn’t properly closed, there’s a problem with the thermostat wiring, a reverse valve issue, incorrect thermostat settings, and more that we’ll cover later in this post.

Causes For Honeywell Thermostat Heat Not Working on Auto

As you begin troubleshooting any issue, you will begin with the easiest to inspect and fix. Now, let’s go right to the bottom of why your thermostat heat isn’t working.

1. You haven’t turned on your furnace.

When you have heating problems with your thermostat, you should first rule out the power source. Is your thermostat set to warm? If the furnace is turned on, check the switch. A furnace switch, which resembles a light switch, is typically situated near your furnace.

If your furnace is on, check your circuit breaker for any tripped switches. Tripped circuit breakers are sometimes the cause of a Honeywell thermostat heat not working. If your furnace has power but does not heat when you switch on the thermostat, proceed to the next step.

2. Inadequately closed furnace door

You have now examined your furnace and it is operational. At this step, you must determine whether the furnace door is properly closed.

Certain heating systems will not operate if the lid is left open or improperly closed. They have a door switch that turns off the power to your furnace when it is partially or fully closed.

In addition, examine your furnace for any trouble codes. If there are any issues, you will generally notice quick blinking lights. The error code reference is located inside the furnace door.

Let’s go on to the next step of troubleshooting after double-checking the door.

3. Connecting a Thermostat

If your Honeywell thermostat is set to heat mode but you only get tepid air, you may have thermostat wiring problems. You must ensure that the wires are properly connected. You can find instructions for connecting your thermostat in the user handbook.

Gently take the thermostat away from the wall to see if the wiring is OK. Some thermostats are equipped with screws or buttons.

It should be noted that wire colors are not uniform, therefore verify the identification of your furnace’s control board to see what terminal each wire connects to. Incorrect thermostat wiring can cause a Honeywell thermostat to flash heat on but provide no heat.

4. Thermostat Configuration

Thermostat Configuration May Cause a Honeywell Thermostat to Blink Heat On But Not Produce Heat

The thermostat setting is one of the most typical concerns that homeowners ignore. Make certain that the thermostat is set to heat. If your thermoset displays the following icons, you can be certain that it is on the heat.

  • Icons of the sun or fire
  • “Heat turned on” or “heat message”
  • If your thermostat does not display any of the following alerts or icons, you must switch to ‘heat.’

After changing the mode, raise the temperature point above the present temperature and wait a few minutes to observe if heat begins to flow through.

It is worth noting, however, that if you are unable to alter the setting on your thermostat, you may have overlooked something when configuring it. In this instance, consult your installer handbook for information on properly programming your thermostat.

Provided you’ve successfully configured your thermostat, you should now see the heat message on the screen. But, if the message “heat on” appears on the display, it can signify one of two things:

Your thermostat is in delay mode, preventing harm to your compressor and other equipment components. Typically, a Honeywell thermostat will flash heat on in delay mode but provide no heat.

If the flashing message does not go away after 5 minutes, you may need to restart your thermostat. You can do so by turning off the power for 5-10 minutes and then turning it back on. If this does not work, you can refer to the user handbook for instructions on how to remove the Honeywell thermostat flashing messages.

5. Reset Your Thermostat

Another simple approach is to reset your thermostat. If you’ve tried suggestions 1-4 and nothing seems to be working, try resetting your thermostat. Nevertheless, before you reset it, make a note of your essential settings because they will all be erased if you reset your thermostat.

How to Reset Your Honeywell Thermostat:

  • Check that your thermostat is turned on.
  • For around 5 seconds, hold down the menu button.
  • Locate and select the Reset option.
  • Next select factory defaults and follow the on-screen instructions.
  • If the problem persists after resetting your thermostat, proceed to the next step.

6. Blower for the furnace

If you’ve tried every troubleshooting advice we’ve provided you and nothing seems to be working, you still have one more option to try. You’ll need to check to see if the cooling is working, and here’s how:

Change your thermostat from heating to cooling and notice how much air comes out of your vents. Is there even any air? If just chilly air is coming in, this could indicate that the heat is not working.

When your thermostat is set to cool, tepid air comes through the vents, which indicates that the reverse valve is misconfigured or not correctly wired.

7. A faulty reverse valve

A faulty reverse valve could be the cause of your Honeywell thermostat’s inability to turn on the heat.

If the reverse valve is not properly wired or adjusted, it could be the cause of your Honeywell thermostat not turning on the heat.

Turn on the fan mode and go to the vent to resolve the reverse valve issue. If the heat is weak or not flowing out fully, we’ll need to check the wiring and make sure everything is in working order. Carry out the following actions:

Remove the thermostat from the wall with care; if it has screws, remove them. Check to see if a wire is connected to the G-terminal. For the fan to work, connect the G-terminal to a wire.

If the G-terminal is connected but your fan isn’t working, you may have a blower capacitor or a broken blower motor belt (for older furnaces.) In this scenario, you should consider hiring a professional HVAC technician to inspect the system.

Last Thought

Honeywell thermostat heat not working on auto is a common problem. Yet, having this difficulty when you need to keep yourself and your family warm can be frustrating. We did our best to provide the most common causes of that problem, as well as potential solutions.

But, if you believe you will be unable to do the task on your own, it is prudent to use a professional service. We hope you found this guide useful.

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