White Rodgers / Emerson thermostats incorporate several safety features to protect your HVAC equipment.
One of these is the compressor lockout, which results in the flashing snowflake icon.
Usually, this goes away after five minutes, but if it doesn’t you may have a problem that needs to be investigated.
What Does the Flashing Snowflake Icon Mean?
In most models, the snowflake icon starts blinking to indicate the compressor lockout mode has been activated. Essentially, it's a safety feature that helps prevent short cycling in your system's compressor by delaying the compressor by five minutes.
This feature is typically found in cool-only, conventional forced air or heat pumps (with or without dual fuel/auxiliary heating).
Compressor Lockout Mode
The compressor lockout is important since it helps prevent:
- Unnecessary wear and tear on the heat pump.
- Extremely high head pressure on the refrigerant (which can lead to refrigerant leaks).
- Inefficient temperature management (especially in lower temperatures where the heat pump can have a hard time warming up the house).
Once the five minutes are up, the blinking snowflake should go away and the A/C will kick in.
Most White Rodgers thermostats have this setting enabled when you configure the thermostat. However, with recent models, this setting is unnecessary since modern compressors already have this built-in.
So in certain older models, you'll have the option to toggle it off. Meanwhile, the recent lineup of Sensi thermostats won't have this feature or allow you to disable it.
Troubleshooting the Flashing Snowflake Icon
In most White Rodgers/Emerson thermostat models, the compressor lockout feature will be indicated by a flashing snowflake icon.
In others, (such as the Emerson Blue Series 12″ models), it will be indicated by a flashing temperature setpoint or a “Starting Soon” message.
The compressor lockout feature, on its own, is no cause for concern. However, if it doesn't go away after five minutes, you'll have to troubleshoot the issue.
So in the following steps, I’ll show you how to troubleshoot a flashing snowflake icon that doesn’t go away.
Step 1. Get the Thermostat Out of Setup/Config Mode
In some cases, your thermostat might be stuck on the programming mode or a configuration menu. So in case they haven't timed out – which usually takes about 15 minutes – you will have to check the display and get the thermostat out of these modes and back into the regular home screen.
So if you notice the display is different: sometimes with the temperature value or time flashing, or a fixed set of numbers on the display, it might be stuck in setup/programming mode.
To get the thermostat out of these modes, you can tap on any buttons assigned as “Run Schedule,” “Done,” or “Exit.”
If you want to know more about the specific setup modes and how to exit them in your thermostat model, check out our list of White Rodgers thermostat manuals.
Step 2. Wait 10+ Minutes
However, if the snowflake icon is flashing on the regular home screen, it might be best to wait so you can be absolutely sure that the issue isn’t the 5-minute timer.
Most users tend to breeze through the troubleshooting process only to find out that the flashing snowflake icon was just the compressor lockout mode. So don't skip this step, make sure you wait!
Ideally, I recommend holding out for a solid 10 minutes so you can safely rule out the compressor protection in the thermostat and in some compressors, the built-in safety delay (which can stack up the total wait time to 10 minutes).
Step 3. Manually Adjust the Thermostat
If you're controlling the thermostat via the app, there might be connectivity issues or bugs within the app.
So to eliminate these right off the bat, try controlling the device manually via the thermostat display itself. When controlling the thermostat manually:
- If you have a heat pump or system with a furnace, check the heating equipment first:
- Set a hold and adjust the temperature a couple of degrees higher than the current temperature and set the system mode to “Heat”.
- Check for the flame icon.
- After that, head down into your heating equipment and see if they power up. Usually, you can hear the furnace or heat pump and see any indicator lights.
- To confirm this further you can also check for warm air coming through the vents.
- After you confirm the heating equipment, then it's time to check if the cooling system is working properly.
- To do this, simply decrease the target temperature by a couple of degrees lower than the current temperature.
- Then, set the system mode to “Cool.”
- The snowflake icon will start flashing, give it a solid five minutes and see if the cooling equipment or blower fan turns on.
- Conversely, you can check the vents for cold air.
If the cooling equipment turns on without any issues, then you can confirm the issue was with the mobile app or the Wi-Fi connection.
In that case, you can take steps to fix them and control the thermostat manually in the meantime.
Step 4. Replace the Batteries on your Thermostat
If the thermostat settings or network issues aren't at fault, the problem may be a power issue.
Power issues can occur because of low batteries, wiring errors, or a lack of a C-wire. So the first thing you should do is to check for a low battery indicator and replace the batteries in your thermostat.
Usually, the thermostat display will indicate low battery, alongside an alert popping up as “Change” or “BATT” on the home screen.
In most models, you can easily replace the batteries by pulling the thermostat off the wall mount and replacing the batteries at the back of the display. Others will require you to remove the front cover only and replace the batteries at the wall mount.
After reinstalling a fresh set of batteries, try again and see if the flashing snowflake goes away. Don't forget to give it 5+ minutes so it completes the delay timer.
Step 5. Soft-restart the Thermostat
To quickly clear out any glitches or quirks in the thermostat, without resorting to a full factory reset, you can perform a soft restart on the thermostat.
- Take out the thermostat from the wall mount.
- Then, remove the batteries.
- Wait a couple of minutes.
- Reinsert the batteries and reinstall the thermostat back into the wall plate.
- Adjust temperatures manually and see if the problem resolves.
In the steps that follow, I talk about troubleshooting the thermostat wires. So to avoid injuries or damage to your equipment, I highly recommend you hold off on diagnosing these components yourself and getting help from a professional, especially if you aren’t skilled at electrical DIY.
Step 6. Check the Thermostat Wiring Terminals
The batteries might not always be an issue, so if the problem doesn't go away, you might have to check the thermostat wiring and possibly, reinstall the connections.
To check the wiring on your thermostat:
- Pull the display panel off the wall mount.
- Then, check the wiring terminals of the thermostat. Make sure the wires are correctly installed at the appropriate terminals.
- If you can't identify the wires by their color codes, you can check the wiring on the other end (HVAC/Furnace control board).
- However, make sure to turn off the power to the HVAC system and also take a photo of the thermostat wiring terminals, so you can easily compare.
- If you find any inconsistencies, make sure to remove the cables and reinstall them accordingly. (Don't forget to turn off the power beforehand and use an appropriately-sized screwdriver).
- After checking the connections and making sure they are installed at the correct terminals, you can try removing each of the cables (at the thermostat end) to check if they are clean and properly stripped.
- After resolving any wiring issues, you can reinstall the thermostat display and restore power.
- Then, when the device reconnects to the HVAC system, you can try adjusting the temperatures manually and see if the flashing icon goes away (after 5-10 minutes of course).
Step 7. Bypass the Thermostat Wires
To confirm that the thermostat is not aggravating the issue, you can try to bypass the thermostat by jumping the R and W (for heating) or Y (cooling) wires.
This will help you see if the HVAC equipment can turn on without the thermostat, giving a much clearer idea of where the fault lies.
To bypass the thermostat:
- Turn off power to the thermostat and HVAC system.
- Remove the thermostat display from the wall mount.
- Remove the R wire from its terminal.
- If you have separate Rc and Rh wires (without a jumper), take out the Rc wire only.
- Then, take out the yellow Y wire (for cooling).
- After that, join the copper ends of the Rc wire and Y wire together, you can use wire nuts or simply twist them together.
- After making sure the jumper connection is secure, you can try restoring power to the thermostat and HVAC system.
- Then, check if the air conditioner equipment turns on without any issues.
If the heating equipment didn't respond while you were manually diagnosing the heat, you can follow the same steps above, but with the R/Rh and W wires.
If the HVAC equipment turns on when you create the jumper and restore power, the issue is definitely within the thermostat. However, if these devices don't kick in, or display symptoms of short cycling, your system or wiring may be to blame.
Step 8. Reset the Thermostat
To make sure any software glitches, schedules, or settings are not interfering with the HVAC equipment, you can factory reset the thermostat.
Depending on the model, you have to press certain button combinations or configure specific settings.
For exact details on this process, make sure to check out this article.
Step 9. Troubleshoot the HVAC Equipment or Thermostat Cable
If you confirm the issue to be the wiring or thermostat equipment using the results from step 7, you can try to diagnose any errors within the HVAC equipment or the entire length of the thermostat cable.
However, these are beyond the scope of this article, so if you're not sure how to proceed, it's best to get help from a professional.
Also, in the case of a flashing snowflake icon, the issues you might typically run across are:
- Clogged filters.
- A clogged condensate drain pump or float switch.
- Loose or damaged thermostat cable 4. Tripped breakers, blown fuses, or switched-off wall outlets/disconnects.
- Low refrigerant.
- Faulty condenser motor.
- Loose contactors or faulty relays.
- Faulty control board.
The list goes on, so if possible, try diagnosing these yourself or getting help from a professional.
The blinking snowflake icon is a normal feature in many White Rodgers thermostats that indicate the 5-minute compressor safety delay.
So ideally, the flashing icon should go away and kick in the cooling equipment after five minutes.
However, if there’s an underlying issue in the thermostat, wiring, or HVAC equipment, the icon will keep flashing and the equipment will not turn on. In that case, you’ll have to troubleshoot the entire system.