Honeywell Thermostat Blinking A Snowflake? (Here's Why)

Ryan Womeldorf
by Ryan Womeldorf
Honeywell thermostats are reliable, but what does that blinking snowflake mean? It can be disconcerting at first, but there is a simple explanation for this icon. Follow along as we explore what the blinking snowflake and delay mode means on your Honeywell thermostat.

Honeywell makes some of the most dependable and popular options for thermostats on the market. Ranging from basic models to smart thermostats, Honeywell has a plethora of offerings that their customers have been using for years.

If there’s a flashing snowflake on your Honeywell thermostat, it is in delay mode to prevent short cycling. This is normal when outdoor temperatures are extreme, but if it persists, you’ll need to address the underlying issue. Fixing incorrect thermostat placement, ensuring your HVAC system is the right size, and keeping up with maintenance and repairs should solve the problem.

Usually, when you see a flashing snowflake, you just have to wait a few minutes until the thermostat is no longer in delay mode. You can also try turning the air conditioning off and back on or resetting the thermostat. Finally, check that your furnace door is closed with the power switch in the “on” position, and that the circuit breaker for the furnace is also on.

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Getting To Know Your Honeywell Thermostat

Whether you have a traditional thermostat or one of the newer “smart” models, the functionality is basically the same. When you program the thermostat, it communicates with your HVAC system on a number of levels.

The temperature is either set manually or on a schedule and the thermostat sends that information to the HVAC system. The HVAC then either puts on the heat or air conditioning to accommodate that temperature request.

Every thermostat also has a number of safety measures in place. The safety measures are meant to protect not only you but the furnace as well. The components in your furnace or air conditioner undergo wear and tear whenever they are used.

When the air conditioner struggles to hit its temperature range, short cycling becomes a problem. That is why most thermostats, even smart thermostats, don’t kick on right away. They need to regulate the HVAC system to prevent those short cycles that can wear and damage your HVAC system.

If you are in the market for an HVAC system, you may benefit from this helpful comparison: SpacePak vs. Unico: Which High Velocity HVAC System Is Best?

What Is Short Cycling?

We’ve mentioned that short cycling becomes an issue when your AC is struggling to hit its temperature range. But what is short cycling, exactly?

You’ve probably noticed that whether your HVAC system is set to heat or cool, it tends to cycle on and off. Depending on temperatures outdoors, these cycles can be as short as 10 minutes or as long as 20 minutes. In general, the more extreme the temperatures, the shorter the cycle.

Short cycling is when the heat or air conditioning cycle happens faster than it should. The furnace or air conditioner is turning on and off at a rapid rate that could damage your HVAC system.

Think of an extremely hot summer day, for instance. As soon as the air conditioner stops blowing cool air, the house begins to get hot again. This forces the air conditioner to work harder and start blowing cool air again sooner than it would on a cooler day.

The same goes for a particularly cold winter day. As soon as the heater stops blowing hot air, the house starts to get cold again. Therefore, the furnace has to work harder and the heater is forced to begin blowing hot air again more quickly.

Unfortunately, short cycling can be very hard on your HVAC system. It causes quicker deterioration and can even lead to necessary repairs or replacement.

What Causes Short Cycling?

Aside from extreme outdoor temperatures which cannot be controlled, there are a few other reasons why your HVAC system might be short cycling.

Incorrect Placement

One simple reason your system could be short cycling is that your thermostat isn’t placed in an ideal location. Your thermostat shouldn’t be in an area that receives direct sunlight. It also shouldn’t be anywhere that a nearby heat- or cold-generating appliance can “trick” it into turning on and off too soon.

Wrong Size

Another possible issue that causes short cycling is when your HVAC equipment isn’t the right size. If the equipment is too big for your space, then your system is very likely to short cycle.

In Need Of Maintenance

If your system has been short cycling, it may need some routine maintenance. Be sure to keep up with routine inspections and cleaning. Even something as simple as dirty air filters can lead to restricted airflow, which can then cause short cycling.

Broken Components

Short cycling may indicate that your system needs repairs. There are several different components that could be causing the issue, from a corroded flame sensor to issues with your condensate switch or breaker.

What The Snowflake Means And Why It’s Flashing

For just about any Honeywell model of thermostat, you will see a snowflake on the display. The snowflake is typically meant to indicate that the air conditioning is on in your home. If you do not see the snowflake, do not assume that your air conditioner is running.

Should you notice the snowflake flashing, it typically means one thing. The flashing means that the thermostat has entered delay mode.

What Is Delay Mode?

A flashing snowflake indicates that your thermostat has entered delay mode, which is a safety measure for Honeywell thermostats. Your system can stay in delay mode for up to five minutes. This is simply the process by which the air conditioner prevents short cycling.

The startup of the air conditioning function is crucial to how the HVAC system runs. When the system short cycles, there is unnecessary wear and tear done to the compressor. With too many short cycles, you could be facing additional damage and shortening the lifespan of your HVAC system.

That’s why delay mode is so important; it protects your HVAC system and helps it last longer. Ultimately, it can even save you money by preventing unneeded damage and extending the lifespan of the system.

However, your thermostat will continue to enter delay mode until you address the issue causing the HVAC to short cycle. As mentioned above, this could be issues with incorrect placement, an incorrectly sized system, or a need for maintenance or repairs.

What to Do When The Snowflake Blinks

So, let’s say you have turned the setting over to “AC” on your thermostat and you are waiting for the air to kick on. Instead, the snowflake on your thermostat display begins to blink. Now what do you do? Is this something you should bring a professional in for?

The first thing to do is just wait. More often than not, the blinking is a delay mode, a simple safety measure to protect the components within your HVAC system. In a matter of minutes, the air should kick on and the snowflake will remain solid.

If the blinking does not stop, the next step is to switch the dial to “off.” Perhaps the thermostat did not properly relay to the HVAC system. By moving the switch to “off” and then back to “cool,” you can start the system up again. That may be enough to get your air conditioning unit working.

Finally, you can try implementing a reset. Each Honeywell thermostat can be reset back to its original settings. That may be enough to clear any potential errors with the device.

When You Use A Saver Switch

Depending on who your utility provider is, your home may or may not qualify for a saver switch. The saver switch is meant to help with the efficiency and usage of energy throughout the home. It can lead to savings on energy bills as well.

If you have the saver switch and notice that your thermostat has the flashing snowflake, it could be that the utility company has locked your device out. When peak demand hours are in effect, they may lock you out to restrict usage.

Depending on the frequency in which this happens, you may want to reconsider the saver switch. Yes, it can potentially help you to save on your utility bills but it may come at the cost of convenience. When it gets especially hot, you won’t want your system down due to lockouts.

Other Potential Fixes For Flashing Snowflake On Thermostat

So, let’s say that you have waited patiently for your air conditioner to kick on, but it just will not start. You checked with the utility company to see if your thermostat has been locked out during peak usage hours. You’re still seeing the blinking snowflake icon, and you’re not sure how to fix it.

If neither of those are the case, there are a few other potential fixes that can be implemented. Some are relatively simple in nature, but effective no less.

Check The Cool Switch

As unbelievable as it may seem, the simplest explanation is more often than not the right one. That said, you may want to check that the switch on the thermostat has been moved to “cool.” It may surprise you how many times the issue is simply that the thermostat is not switched to the right setting.

While you are checking the setting of the thermostat, check your set temperature point too. It may simply be that the temperature that you set is above the current temperature. In that case, the air conditioner wouldn’t kick on because the temperature is already below your setting.

Close The Furnace Door And Turn It On

A call for cool is indicated by the snowflake icon or the words “cool on.” It simply means that the system has been told to turn on the air conditioning.

Should your thermostat indicate a call for cool, then you will need to go check out the furnace itself. When this action comes up, ensure that the furnace door is closed securely. More importantly, make sure that the power switch on the furnace is set to the “on” position.

For one reason or another, your furnace can get tripped into the off position. When that happens, there is nothing that you can do until the switch is flipped to the “on” position.

Check The Circuit Breaker

Your thermostat is not the only device in your home that has built-in safety measures. Like the thermostat, the furnace has built-in safety measures to prevent damage to the system or, worse, fires from occurring.

In some instances, one of the safety measures within the furnace can become triggered. If those safety functions get triggered too frequently, the furnace may shut off until it is reset. This is a safety feature to prevent things like the gas valve from remaining open.

Start by checking the circuit breaker for the furnace first and ensuring that it’s on. Sometimes it can be as simple as a breaker tripping, cutting the power to the HVAC unit.

Contact An HVAC Contractor

If you’ve gone through the steps above and can’t identify the problem, you may need a service technician to come out and reset the unit. This is especially true if your cooling system has worked in the past but is not working currently. Generally, this indicates that there is a component of the system in need of repair.

Do You Need Your Thermostat Repaired or Reprogrammed?

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Issues Related To First Time Installation

The circumstances may be a bit different if you have just set up the thermostat or are setting it to “cool” for the first time. There are a couple of things that you can do to troubleshoot the issue. Keep in mind that these steps involve the wiring. If you don’t feel comfortable checking the wiring, call in a professional technician to handle the issue.

Ensure Wiring Is Connected Properly

When you are installing your Honeywell thermostat, make sure that the wiring is matched up correctly from the old thermostat to the new one. If you don’t see separate wires to the R and Rc terminals, then they must be connected.

For some thermostats, the connection can be made by a jumper wire connection. On others, the connection is made using a slider switch that has settings called “1-wire” and “2-wire.” Check your installation guide to see what you have.

Check For Proper Configuration

Another potential issue related to the installation is proper configuration. You cannot just plug and play any old thermostat, so make sure that your Honeywell thermostat has been properly configured to your HVAC system.

Check out your user and installation manuals before installing. Confirm that your thermostat is the proper configuration for your HVAC system type as well as the stages of your equipment. If everything is as it should be, you can proceed with the installation.

Honeywell thermostats may face a variety of other issues, such as connection issues. You can learn more about these issues and troubleshooting here: Honeywell Wi-Fi Thermostat Connection Problems


A flashing snowflake means your Honeywell thermostat is in delay mode, and all you need to do is wait. Generally, delay mode only lasts five minutes, and it’s a safety measure that prevents short cycling. However, if your thermostat persistently displays a flashing snowflake, there may be an underlying issue to take care of.

Ensure the size of your HVAC system and placement of your thermostat are both correct. Keep up with routine maintenance and any necessary repairs as well.

In some cases, simply turning the air conditioning off and back on will prevent the system from going into delay mode. You can also try resetting the thermostat. Another quick fix is to check that the furnace is on and its door is closed, and that the circuit breaker for the furnace is on.

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Ryan Womeldorf
Ryan Womeldorf

Ryan Womeldorf has more than a decade of experience writing. He loves to blog about construction, plumbing, and other home topics. Ryan also loves hockey and a lifelong Buffalo sports fan.

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