A thermostat keeps your room temperature constant. If you have a Honeywell thermostat that gets blank, your first instinct would be to fix it as soon as possible. For that, you need to be familiar with the reasons behind it.
Your Honeywell thermostat is blank primarily due to power issues, incompatible parts, broken thermostats, and manufacturer defects. To fix it, troubleshoot the power issues like wires and breakers, use compatible parts, replace the old thermostat, and call professionals if needed.
After much research and consultation with HVAC professionals, I have found and shortlisted the primary reasons behind a blank Honeywell thermostat and ways to fix them. So, stick to the end.
Check out our list of top-handpicked products for all your electrical, appliance, and HVAC system needs to keep your home running smoothly.This post includes some affiliate links.
1. Power supply issues and electrical problems
The primary reason behind a thermostat going blank is the power supply issues.
It includes low or dead batteries, switches turned off or tripped breakers.
The screen will remain blank if the thermostat is not receiving any power.
The thermostat is turned off
When someone accidentally turns off the thermostat, and you are unaware of it, it is evident that you will see the screen blank.
Before troubleshooting this problem, check the switchboard and see if the device switch is turned on.
Turn on the switch and see if the screen works. If yes, you have solved the problem. If not, check for other issues.
Overloading or short circuits can trip the breaker.
Generally, the HVAC system contains a dedicated breaker, and the thermostat is also connected.
Sometimes, the thermostat stays connected to a different breaker.
If that breaker somehow trips due to overloading, the device’s screen will stay blank.
Overloading occurs when you connect too many appliances to the breaker.
The rule is to load only 80% of the breaker and empty the remaining 20%.
Another reason behind the tripping is a sudden power surge.
The breaker will trip for safety to avoid severe electrical issues.
Check the breaker once if the thermostat screen is blank.
If it has tripped, check the load, reduce it, and turn on the breaker again.
If the breaker’s handle is turned off, press it on until you hear the clicking sound.
But if the handle is stuck at the center, turn off the breaker entirely, wait for some seconds, and turn on and press the trip until you hear the clicking sound.
If the breaker trips again, there has been some electrical fault. Keep the breaker off and call a professional to fix it.
Battery-related issues are plenty. The battery might be low, dead, corroded, and damaged due to regular wear and tear.
Not all, but some Honeywell thermostats will run on batteries.
If the battery is the main issue, your device will remain blank.
In all these cases, you must replace the battery.
The thermostat batteries must be replaced at least once a year.
If you haven’t changed it, the batteries will have low or no charges and wear and tear over time.
The Honeywell thermostat uses two AA or two AAA alkaline batteries.
If the batteries are incompatible, the thermostat will again stay blank.
So, ensure you are using the right one.
To change the batteries of the Honeywell thermostat:
- The Honeywell thermostat will have a button labeled PRESS.
- Press the button and release the battery pack.
- Replace the batteries with the new batteries, and dispose of the old batteries.
- Put back the battery compartment and check the thermostat screen.
2. Thermostat display problems
Most Honeywell thermostats are new models with a touchscreen.
Like smartphones, the screens can be adjusted according to the required brightness.
So, check it closely if you think the screen is blank. Sometimes, the screen will seem blank from too far.
Otherwise, you will waste a lot of time troubleshooting the thermostat in different ways and end up with more damage.
The thermostats are designed to full brightness by default. You can adjust it according to your needs.
If you think the screen is blank, touch the screen and see if the display turns on. Also, clean the screen regularly.
3. Problems with thermostat settings and programming
A programmable Honeywell thermostat will function well and remain okay in the long run.
If the settings are incorrect, your thermostat will malfunction and go blank.
For example, the panel will click in when you mount the Honeywell thermostat to its base.
You will not hear the clicking sound if you do not press the device properly.
In such a condition, the thermostat screen will not turn on.
You can fix the problem by pressing the thermostat and holding it until you hear the clicking noise.
While setting the thermostat to turn the heat or cooling setting up or down, be careful while doing it. Follow the manual before you approach anything.
If anything goes wrong, the in-built features inside the HVAC thermostat will turn off the device and make the screen go blank.
If the smart Honeywells are connected to your phone, it will turn on or off when you enter or exit a certain radius of your house.
In that case, the other people staying will see a blank thermostat.
It is a natural problem, and you can fix it by disconnecting the device from the mobile or connecting it with the mobile phones of other members so that they don’t face any problems.
4. Damaged wiring or improper installation
The thermostat will have multiple wires for functioning, and if any wires get badly damaged, the screen will not turn on unless you repair the wires.
Over time, the wires can also become loose due to the daily wear and tear, causing the thermostat to go blank.
Another situation where the wire problem is witnessed is when you have recently installed or done any wiring repair in the thermostat.
To troubleshoot these issues, you must check the wire connections and ensure they are correctly wired or need to be rewired and fixed.
To troubleshoot the problem:
- Turn off the breaker powering the thermostat.
- Open the cover plate and have a look at the wires.
- Check for loose or damaged wires. If any wires are loose, screw them and tighten them to their place. You must call a professional to fix damaged, pinched, broken, or burnt wires.
- If everything is fine, check whether the wires are connected to the correct terminals.
- There will be 5 wires. There might also be 4 wires if you have an old Honeywell model where old wires are used to install the thermostat.
- W is for heating, G is for the fan, Y is for cooling, Rc is for heat pump and furnace power, and Rh is for air conditioner power. These wires need to be connected to their corresponding terminals, which will be labeled with the same letters.
- Some Honeywell thermostats will have only one R wire, whereas others will have Rh and Rc wires. If you have two wires, connect them together to the R terminal.
- Put back the cover plate, turn on the breaker, and test the thermostat. If you still can’t fix it, call a professional.
5. Faulty or blown fuse
The fuse is a vital part of the thermostat. Several thermostat models have an in-built fuse to protect the device from damage during power surges.
If there is a surge in the electrical supply, the fuse must have been blown up, and you are unaware of it.
Therefore, the thermostat will go blank.
Sometimes, the fuse becomes faulty due to manufacturing defects.
In this case, you must replace the old fuse with a new one.
To locate and replace the fuse:
- Open the Honeywell thermostat’s lower compartment.
- Remove the screws if needed to access the control board panel where you will find the fuse.
- Find the amp label or the voltage rating near the fuse. It will be close to 3-5 amps.
- Once you have found the fuse, please replace the damaged one with a new one.
- Ensure you are using the fuse that matches the make and model of the Honeywell thermostat. If needed, take out the fuse and take it to the market to receive the exact one.
6. Open furnace door
I ever wondered if an open furnace door could also lead to a blank thermostat screen until I witnessed it.
Last week, when I went to turn on my thermostat, the screen remained blank. There were no severe issues, as explained above.
So, it took a lot of work to get to the bottom of the problem. After a lot of examination of the HVAC systems, I spotted an open furnace door.
I closed it and tested the thermostat, and it was immediately fixed.
The heating system contains a door allowing technicians to enter and access the internal parts during any repair or maintenance. It should be closed during operation for safety.
The Honeywell thermostats have an in-built safety measure that signals the thermostat to remain off from operating if they sense any danger.
So, if your thermostat has a blank screen and ruled out the other reasons, check the HVAC door once.
7. Closed furnace
The Honeywell thermostat generates a power source from a low-voltage transformer in the furnace.
So, if the furnace is flipped off, the thermostat will not be able to generate power and work correctly.
That is the reason sometimes your thermostat goes blank.
Check the furnace once and see if it is off. Locate the switch and turn on the furnace.
Close the door; otherwise, the thermostat will again remain blank.
The breaker may have tripped if the system still does not turn on.
Go to the breaker panel and find the breaker labeled as a furnace.
Move the lever to the ON position and turn on the system.
8. Triggered safety switches
The Honeywell thermostats have in-built safety features which protect the HVAC system from overheating.
When the system detects temperatures exceeding the safe temperature range, the high-limit switch will trigger and turn off the furnace.
So, the thermostat will also turn off and have a blank screen.
It occurs when the airflow of the HVAC system has some problem that needs to be attended to faster.
Usually, it kicks back when the temperature comes back to normal.
To do it manually, locate the high-limit switch inside the HVAC system and turn it on again.
If the switch is frequently tripping, call a professional to fix it.
Another safety switch is the float switch which is triggered when the system is detected with moisture.
For safety purposes, the switch turns off, and so does the thermostat screen.
Check the HVAC system’s drain pan to ensure no clogging.
Then, turn on the float switch.
If you cannot fix the switches, reset your thermostat.
The steps would be slightly different based on what model you have.
Below is a brief guide to resetting a few Honeywell thermostat models.
For more options, check the owner manual.
Honeywell 1000 and 2000 series (battery-powered)
- Turn off the breaker if your thermostat is attached to the wall power.
- Remove the device cover plate and reach the battery compartment to access the batteries.
- Remove the batteries, and again put them back into the thermostat. Let them stay for 5 seconds.
- Please remove the batteries again, and place them back again in the correct direction.
- Reattach the thermostat and turn on the breaker. Test the thermostat.
Honeywell 4000 series
For this model, hold the SET and RUN buttons together.
After a few seconds, the thermostat will reset and return to its default routine and settings.
Honeywell 6000 WF series
Hold the UP arrow and FAN button together.
While holding them together, set the numbers on the right to 90 and the left to 1.
Press DONE and reset the thermostat. It will come back to the default settings.
Honeywell 8320 and 8580WF
- In the thermostat, tap on SYSTEM.
- Press and hold the box popping on the center of the screen.
- Now set the left number to 0710 and the right one to 1.
- Select DONE, and your thermostat will reset to the default settings.
Honeywell 9000 series
Select Menu → Preferences → Restore Factory Defaults → Confirm (when asked) → Are you sure? → YES.
Select the MENU button and keep scrolling until you select the RESET button.
When the question appears ARE YOU SURE?, select YES.
Honeywell Lyric and Smart Round Thermostats
- Press and hold the CLOUD icon.
- Press and hold the DOWN icon.
- Choose the RESET button when it pops up on the screen.
9. System compatibility issues with heating and cooling equipment
Suppose you have recently done any repair or maintenance in your cooling and heating systems.
In that case, you might have added some parts incompatible with the Honeywell thermostat.
Or, the thermostat may be incompatible with the HVAC system.
Incompatibility between the parts and the HVAC system prevents the thermostat from working. As a result, the screen remains blank.
To fix the problem, replace these parts or the thermostat and get the one that suits your HVAC.
Call a professional to replace the incompatible parts you have used in the heating and cooling systems.
For an ideal thermostat type for your HVACs:
- Low-voltage HVAC systems that need 24-volt, maximum thermostats will be compatible with them.
- You must check the owner’s manual for high-voltage or direct-line HVAC systems that use 110 to 240-volt power sources. They will need specific types of thermostats.
If you plan to get a new Honeywell thermostat, remember that some models are compatible with only a few HVAC stages, which will be mentioned in the owner’s manual.
Consult the manual, and hire a professional to correct the incompatibility issues.
10. Manufacturer defects and recalls
Sometimes, there is no such problem as explained above, but your Honeywell thermostat remains blank.
It is confusing for beginners. In today’s world, the internet is one of the great resources to solve maximum problems on our own.
If you cannot find solutions to your blank Honeywell thermostat online, the device has manufacturing defects.
So, you need to hire a professional to fix the problem.
11. A broken or old thermostat
If you have checked and troubleshoot all the above problems, then the lifespan of the Honeywell thermostat is over.
If your thermostat has given you services over 10 to 15 years, it is time to change the thermostat.
Over time, the wires and the internal parts will wear out.
It won’t work fine even if you repair or change the wires.
Replace your old Honeywell thermostat with a new one.
The recent Honeywell thermostats have many innovative features compatible with modern-day HVAC systems.
If you reached the end of the article, you have known all possible causes behind a blank Honeywell thermostat. Don’t panic if you are facing issues. Please review the problems I have explained, see which one you are facing, and troubleshoot them.
Resetting can solve a lot of problems. Inspect the steps I have mentioned for resetting the thermostat. Different Honeywell models will have different resetting steps.
Check the owner’s manual for the proper steps if your model resetting method is not in this article. If you are not confident enough, hiring professionals and asking them to solve it is best.
Why is my Honeywell thermostat saying WAIT?
When your thermostat pops WAIT, it is because of the in-built safety measures that protect the HVAC compressor from damage. The message means that the device is waiting to activate the system. It should go away once the system activates, but if it doesn’t, call a professional.
Do all the Honeywell thermostats have batteries?
All the Honeywell models do not run on batteries. Those that run will need AA or AAA alkaline batteries.
Why is the fan working with a blank thermostat screen?
It happens because you have turned on the fan mode in your thermostat. It does not require any battery to run.
Reference: Thermostat Wikipedia