Honeywell Thermostat Flame Icon Blinking? [Fixed]

Last updated: August 16, 2023

Is your Honeywell Thermostat Flame Icon Blinking? Don’t Panic! Follow these simple troubleshooting steps to quickly diagnose and fix the issue and get your heating system up and running again in no time.

A blinking flame symbol on a Honeywell Thermostat implies your thermostat has been set to heat mode  and there is a call for heat. This is known as the time off delay and is there to prevent your Heat pump compressor from short cycling.

Time off delay will typically  not take more than 5 minutes. If 5 minutes elapses and the flame symbol continues to flash, there could be another issue with your heating system. These include:

1) Power Loss

2) Blown fuses

3) Open high limit switch

If the issue is due to a time off delay, simply wait for the delay to elapse, typically about minutes. Otherwise, check for power loss, reset the high limit switch.

Read also: Honeywell Thermostat Says Waiting For Equipment [Fixed]

Possible causes for a flame icon blinking on a Honeywell thermostat + Solutions

Possible CausePossible Solution
System time off  delayWait for the delay to end
Power loss to the outdoor unitCheck for power loss; contact an electrician if needed
Power loss to the air handlerCheck for power loss; contact an electrician if needed
Blown fusesCheck and replace blown fuses
Open high limit switchReset the high limit switch

System time delay

Some Honeywell thermostats may have a programmed delay that prevents the heating system from turning on too frequently or too soon after it has turned off. 

This delay can last for up to 5 minutes, so if the flame icon is blinking during this time, it could be a normal part of the thermostat’s operation.

You don’t need to do anything yet. It is best to wait for at least 5 minutes for the ‘wait time’ to elapse before you start troubleshooting any other issues

Power loss to the outdoor unit

The outdoor unit of your heating system requires electricity to function. If there is a power loss to the outdoor unit, your HVAC’s normal operation will be disrupted.

 That means that if you are using a heat pump, you won’t have heating in your home despite the call for heat from the thermostat. That could be the reason there is a flame icon blinking on your thermostat.

Power loss to the air handler

The air handler in your heating system is responsible for circulating  air throughout your home. If there is a power loss to the air handler, it can cause your heating system to malfunction and display a blinking flame icon. Power loss to the air handler is usually caused by tripped switches.

This is not unusual especially if you had someone work on your HVAC system recently. They might have forgotten to turn the switch back on. Other times, when there are power surges somewhere within the HVAC system, circuit breaker would trip causing power loss to the air handler.

 Blown fuses

Any HVAC system is made up of several components that can have fuses. Fuses protect the internal part from damage when there are power surges. These fuses when blown can cut power supply and eventually prevent the air handler or furnace from turning on.

 This is another good reason your thermostat is flashing a flame icon without heat coming on.

Open high limit switch

The high limit switch in your heating system is a safety feature that turns off the heating system if it becomes too hot. If the high limit switch is open,it will cause the gas valve to close and prevent the burners from igniting.

That means that the furnace wont turn on despite receiving the instruction to do so from the thermostat. However, the thermostat will flash the flame symbol just to let you know that there is a call for heat.

Troubleshooting steps to fix a blinking flame icon

If you’re experiencing a blinking flame icon on your Honeywell thermostat, there are some troubleshooting steps you can take to fix the issue:

Check for power loss

Power loss to the outdoor unit or air handler can cause your heating system to stop working and trigger a blinking flame icon on your thermostat. 

Troubleshooting power loss to your HVAC units should typically involve checking the circuit breaker to make sure there  are no tripped circuit breakers. 

You might also want to take a look at the disconnect which is typically located outdoors near the point where the refrigerant lines enter the home. Remove it and check if it is properly connected or if it has a blown fuse for possible replacement.

Read also: White Rodgers Thermostat Flame Icon Blinking [Causes + Fixes]

Reset the high limit switch

If the high limit switch in your heating system is open, gas flow to the ignition will be stopped and the problem can be fixed by resetting it. And resetting it involves turning off the furnace for a couple of minutes before turning it on again.

Check the heating system’s components

If none of the above troubleshooting steps solve the issue, it’s possible that there’s a problem with one of the heating system’s components, such as the igniter or flame sensor.

If you are a DIY person you might want to explore further on how to test the two parts for continuity and how to clean them.  If not, it’s best to contact a licensed HVAC professional to diagnose and repair the issue.

Read also: How To Change a Honeywell Thermostat From Celsius to Fahrenheit In Seconds


 Is it safe to troubleshoot and fix a blinking flame icon issue on my Honeywell thermostat myself?

It depends. If you are comfortable with handling heating system components, go for it. Some troubleshooting steps, such as checking the thermostat batteries or air filter, are safe and easy to do yourself. However,  if you’re not comfortable performing the steps, it’s best to contact an HVAC professional for help.

 How often should I perform maintenance on my HVAC system to prevent unforeseen  issues?

It’s recommended to perform maintenance on your Honeywell thermostat and heating system at least once a year, ideally before the start of the heating season. This can help prevent issues such as a blinking flame icon and ensure that your heating system is running safely and efficiently.

What does “heat on flashing” mean on my thermostat?

 “Heat on flashing” on a thermostat usually indicates that the thermostat is calling for heat but the heating system is not responding or not working properly. This can be due to a variety of issues, such as power loss, faulty components, or issues with the thermostat itself.

Can a malfunctioning thermostat cause “heat on flashing”?

Yes, a malfunctioning thermostat can cause “heat on flashing” issues. Make sure to check and troubleshoot your thermostat before assuming that the issue is with the heating system.

Read also: Honeywell thermostat EM heat meaning

Final thoughts

In summary, a blinking flame icon on a Honeywell thermostat can indicate several issues related to the heating system or the thermostat itself. 

We hope that at the end of this guide you have fixed the issue at hand. Otherwise regular maintenance of the heating system and thermostat can also prevent these issues from happening in the first place.

Additional resources


Similar Posts