Honeywell Thermostat Questions

15 Common Questions About Honeywell Thermostats

Honeywell manufactures some of the most dependable and popular options in standard HVAC thermostats as well as smart thermostats. They have a huge number of models to choose from at an affordable price point. This is a list of common questions to troubleshoot your Honeywell thermostat and get it back in great working order.

1. Why Does My Honeywell Thermostat Have a Flashing Snowflake?

2. How Do I Use Auxiliary Heat on a Honeywell Thermostat?

3. Why Does My Honeywell Thermostat Say Cool On But Has No Air?

4. Is My Honeywell Thermostat Following a Schedule for Recovery?

5. Why Won’t My Honeywell Thermostat Turn On Heat?

6. Why Does My Honeywell Thermostat Say “Return”?

7. How Do I Use the Honeywell Thermostat Humidity Setting?

8. How Do I Calibrate a Honeywell thermostat?

9. Why Won’t My Honeywell Thermostat Turn Off?

10. Why is My Honeywell Thermostat App Not Working?

11. Why Does My Honeywell Thermostat Say Em Heat?

12. Why Won’t My Honeywell Thermostat Fan Turn Off?

13. Where Is My Honeywell thermostat Gas or Electric Switch?

14. Does a Honeywell Thermostat Need a Jumper Wire?

15. Why Does My Honeywell Thermostat Keep Changing Temperature?

Why Does My Honeywell Thermostat Have a Flashing Snowflake?

All Honeywell thermostats, no matter the type of model, have a symbol showing you when the air conditioning is turned on. It can be a snowflake or it may say “cool on.” When the air conditioner is actually running it will be a steady symbol, but you may notice it flashing at times. This indicates that your HVAC system is in a delay mode. This occurs for up to 5 minutes when it is getting ready to turn on again to maintain the temperature that you set it on. It keeps the unit from short cycling and ruining interior components. As soon as you feel cool air coming into your home through the vents, the snowflake will be solidly lit up and not flash. If the snowflake doesn’t return to solid, you can switch your dial to “off,” wait a few seconds, and then turn it back on “cool.” This will reset the thermostat for you.

How Do I Use Auxiliary Heat on a Honeywell Thermostat?

Auxiliary heat or emergency heat are the terms on different Honeywell thermostats that actually mean the same thing, although one is automatic and the other you can turn on. Auxiliary heat will be on at all times in case you need it when it’s very cold. If the temperature reaches 40 degrees F or lower, the emergency heat will start. It will run your backup heating source of a heat pump or heat strips at the same time as your heater is running the compressor to heat your home up much quicker. If you set your thermostat between 60 and 68 degrees, the auxiliary heat will not turn on. If it becomes very cold in your home, you can press the emergency heat on to give you quick heating to raise your temperature.

Why Does My Honeywell Thermostat Say Cool On But Has No Air?

Your Honeywell thermostat should indicate that the cooling system is on by displaying “Cool on” or a snowflake symbol, depending on your distinct model of the thermostat. It may display that the cooling system is on, but you don’t hear the compressor engaging or the blower blowing and no cool air is coming from the vents. This means that it has reached the temperature you set the A/C  on and is pausing until it reaches a higher temperature to turn back on and run producing cold air.

Is My Honeywell Thermostat Following a Schedule for Recovery?

Honeywell advanced and smart thermostats have a special feature called the Recovery Mode. When you set a program for your temperature to be a certain amount, such as 74 degrees F at the time you get home from work, the recovery mode will start cooling your home down in advance. It takes some time to cool down several degrees in your home, so the cooling cycle to reach the programmed temperature will start before you get home in order to reach the correct temperature at the specific time you set.

Why Won’t My Honeywell Thermostat Turn On Heat?

There are several different reasons why your Honeywell thermostat may not turn the heat on. If your thermostat displays “heat on” but no warm air is being produced, it may be off in order for the temperature to get low enough and it will restart to warm your home to the set temperature. If the “heat on” display is flashing and there is not any warm air there are several reasons why this could be happening. If your thermostat was programmed for a specific temperature and you adjusted the thermostat manually, it may blink as the compressor is forced to restart. If you have just switched the thermostat from cooling to heating or heating to cooling, the thermostat will need a bit of time to adjust itself. When you have a weak battery or you change the battery, your thermostat may blink while it resets itself.

Other more technical issues may include dirty air filters, dirty coils, broken cords, air blockages, or a dead blower motor. In these cases, if you aren’t a DIY homeowner you may want to call a certified technician.

Why Does My Honeywell Thermostat Say “Return”?

On programmable and smart Honeywell thermostats, you can set times at which you want your home to be a specific temperature and it will automatically run as needed to reach that temperature. If it displays, “return” it simply means that it is returning to a programmed setting that you previously set, but have overridden it by making a manual adjustment to the program.

How Do I Use the Honeywell Thermostat Humidity Setting?

If you live in a warm area, your home will probably get humid in the late spring, summer, and early fall. This is because the difference in the outside and inside temperatures causes humidity to fog up your windows in your home. To turn on the relative humidity control, you turn it clockwise. You then set your thermostat according to the outdoor current temperature, using the correct number as a setting below:

  • Negative 20 degrees F or lower-15
  • Between negative 10 and negative 20 F-20
  • Between 0 and 10 F-25-30
  • Between 10 and 20 F-35
  • Warmer than 20 F-40
  • Use the setting of 50 or 60 to increase the humidity in your home

Expert Tip: If you set your relative humidity to somewhere between 30 and 50 percent, your home should be comfortable all year round without the need to change the setting on your thermostat.

How Do I Calibrate a Honeywell thermostat?

Honeywell thermostats are very reliable and can hold the temperatures in your home at a mere 1 degree of accuracy from the set temperature. To make sure your thermostat is accurately recording the temperature takes only a few moments. You tape a glass tube thermostat to the wall about 2 or 3 inches from the thermostat. Wait about 15 minutes for the mercury inside to stabilize and show you the ambient temperature in that area of your home. If it varies by more than one degree, you should calibrate it.

You should open the face of your thermostat and clean it out of dust or debris with a soft brush. If you have a mercury vial that looks like the glass thermometer you taped to the wall, then use a level to make certain it is straight. If you don’t have a mercury vial, then you’ll adjust the calibration screw. You need to insert a screwdriver into the screw in the middle of a curly metal piece. Turn it back and forth very slowly until the contacts open and then again until they close. This will reset them. Also, look for loose wiring in the thermostat. You can now recheck the temperature for variances.

Why Won’t My Honeywell Thermostat Turn Off?

If your A/C or heat is on and it seems to be way too cool or warm, respectively, then you can check your thermostat temperature. You can turn the A/C temperature down to make it turn off or turn the heat temperature higher to make it turn off. Wait about 15 minutes after making an adjustment to set if it cuts off. You can then reset the temperature you want it to be. If this still doesn’t work, reset your thermostat by turning it to “off.” Slide a coin into the slot on the battery door and open the door. Take the batteries out, put them back in backward. Wait a few seconds, remove the batteries and put them back in correctly, and shut the door. Now turn your thermostat back on and set it to the temperature you want.

Why is My Honeywell Thermostat App Not Working?

This may happen occasionally and the easiest way to return it to working order is to reinstall the app. On your Honeywell screen, press and hold the “Home” icon on the screen. Navigate to “settings” “WAC” “Disable” and “Setup”. This will uninstall the app and reinstall it for you. Then you reinstall it with the on-screen assistance for the Honeywell Home App.

Why Does My Honeywell Thermostat Say Em Heat?

If your Honeywell thermostat displays “Em Heat” it is a sign that your emergency backup heat is enabled. When you switch on the Em Heat, your heater will use a backup method of heating your home when it’s really cold outside. It relies on an electric heat pump, heat strips, or a backup gas furnace to warm your home better than the main heater. Emergency heat is much more expensive to run, so it’s recommended when your system malfunctions and you need to stay warm until a repairman arrives.

Why Won’t My Honeywell Thermostat Fan Turn Off?

Your thermostat fan is generally set on “Auto” for automatic functioning, no matter if the heater or the air conditioning is running. The fan will run until the air reaches the temperature set on your thermostat, then the system stops running and automatically turns the fan off. The other setting near the fan is “on.” This will cause the fan to run continuously even if the system is not heating or cooling and it will distribute the air in your home.

Where Is My Honeywell thermostat Gas or Electric Switch?

If you are a DIY homeowner and you install your own Honeywell thermostat, you have two choices in the operation system: gas or electric. After wiring the new thermostat, attaching it to the wall, and putting in batteries, you need to set up the fan operation switch. It will be factory set to either the letter “F” or “gas or oil.” If your system uses gas or oil for heat, leave the switch in this position. It’s on the left side of the thermostat near the bottom or center, depending on your model. Otherwise, change the switch to the letter “E” or “Electric or Heat Pump.”

Does a Honeywell Thermostat Need a Jumper Wire?

The short answer to this question is maybe and sometimes. It actually depends on the wiring in your home that is connected to your old thermostat. Your very best bet is to take a picture of the wiring so you can see which one attaches to which screw. The labels may have worn off the wires or you may not be able to see the markings on the metal component to which they attach. If you have both an “R” and an “Rc” wire connected to the far right two set screws, then you don’t need a jumper. If you only have the “R” wire, then you will need to connect a jumper wire on the set screws with one end on each of the screws farthest to the right.

Why Does My Honeywell Thermostat Keep Changing Temperature?

On a programmable Honeywell thermostat, the most likely reason is that the unit is in the program mode. Look for the “hold” button, then turn the temperature up or down manually to the setting you desire. Press “hold” once and “hold” or “permanent hold” should display on the thermostat. Another common reason is if you didn’t program all 7 days of the week on your thermostat. It will then revert to factory settings of 85 degrees F on days that aren’t programmed.

I hope you enjoyed this list of some of the most common questions asked about Honeywell thermostats. Be sure and look at the links for instructions, diagrams, owners’ manuals, and videos on how to execute troubleshooting measures and fixes. I’ve been a DIY homeowner with over 30 years of hands-on experience in all aspects of homes, including electric components of all types. Please leave a message in the comments to tell us how you liked this article.