
No one wants to come home and find a blank thermostat, especially during a hot summer or cold winter.
A Nest thermostat is the most crucial component of your HVAC system. The device optimizes your HVAC system, offers consistent temperatures, and saves you money when adjusting your home’s temperatures.
But when the Nest thermostat screen goes blank or black, you can’t program your cooling and heating settings. This may signal a serious issue with your HVAC system.
This article discusses some of the most common reasons your Nest thermostat screen might be blank and how you can resolve the problem.
Why Does Your Nest Thermostat Screen Blank?
Reason 1: Low battery
If your Nest thermostat screen is blank, the first thing you need to do is to check the batteries.
Chances are that thermostat batteries are drained or low and, therefore, your device can’t power on.
The major cause of your Nest thermostat screen going blank is drained or low battery.
Thermostats that are improperly powered can’t send signals to your HVAC system and will display a blank screen.
Therefore, if your Nest thermostat screen is blank, chances are that its batteries are dead or low.
How to fix: Troubleshoot batteries
To address the blank screen issue:
- Charge or replace the batteries and see if your thermostat turns on.
- The need to recharge or replace the batteries depends on the type of batteries used on your Nest thermostat.
- If your Nest is a thermostat model that uses AAA alkaline batteries, you will need to replace the batteries based on this type. While the thermostat battery can last up to 5 years, you may need to replace it earlier before that.
- Nest Thermostat E and Nest Learning Thermostat come with built-in batteries that are automatically chargeable via your HVAC system. However, these thermostats might fail to charge automatically. This might cause your thermostat screen to go blank. So, you’ll need to manually charge the batteries using the recommended USB cable.
- If your thermostat has stopped working, it’s an indication that you need to change the batteries. It’s advisable to test your thermostat batteries annually to ensure they still have a charge.
Reason 2: Wiring issues
Your Nest thermostat has several electrical connections serving various functions, including powering the screen display and enabling your thermostat to communicate with your HVAC system, among others.
If your thermostat runs off of electric power, this could be a symptom of a wiring problem.
Over time, the connection between the thermostat and the electrical line might be faulty or loose. This could cause the thermostat screen to go blank.
A newly installed thermostat is likely to experience wiring issues if it is installed by an inexperienced person. This issue may prevent your thermostat from obtaining power, resulting in a blank thermostat screen.
How to fix: Call an HVAC expert
- Contact a certified HVAC technician to diagnose the wiring to your thermostat and determine what kind of damage has been done.
- The technician will help diagnose your HVAC system and make your Nest Thermostat work again.
- The expert will also handle any wiring-related problems in your house.
Reason 3: The HVAC system and its circuit breakers
If your Nest thermostat screen is still blank or black, the cause of the problem could be no power coming from the rest of your HVAC system.
If your HVAC is experiencing issues associated with a blown fuse or a circuit breaker switched off, this can cause the Nest thermostat not to be charged, and as a result, give you a blank screen.
Your Nest thermostat is normally connected to your home or business via the main electrical system.
Sometimes due to high electric voltage, the fuse box can blow and the wiring burn out. A loose or damaged wire can cut the electricity to the unit, thus causing your Nest thermostat screen to blank due to a lack of power supply.
When a circuit breaker trips, it shuts off power to your thermostat, giving you that blank screen.
How to fix: Call an HVAC professional
- Check the fuses, breakers, and any safety switches associated with your HVAC system and, if necessary, reset them.
- Always follow the necessary safety precautions. When diagnosing the inside of the HVAC system, remember to turn off the power supply. Also, be careful when flipping any switches or breakers.
- If a breaker has tripped, flip the switch back on to reset the power connection. Replace blown fuses.
- However, fixing HVAC issues is something you can’t do on your own completely.
- Contact a certified HVAC professional to properly configure the wiring modifications, fuse replacements, and the HVAC system to meet the appropriate electrical requirements. If your entire HVAC system incurred damage, consider replacing it.
- The HVAC expert will also inspect the wiring issues within your house and repair them.
Reason 4: Nest display detached
Another reason for the screen black is an inaccurate connection of your Nest thermostat with the base.
While this issue looks common sense, if your thermostat display has detached from its base, the screen can become unresponsive and remain blank.
Sometimes, at first glance, you may not notice that your thermostat display is detached. But after looking keenly, you may spot a slight gap between the display panel and the base. That’s an indication of detachment.
The detachment could be caused by several factors such as accidental detachment due to a degraded glue layer or other external factors.
How to fix: Properly attach the thermostat with its base
To fix the connection problem:
- First, detach the thermostat from its power and unplug all cables to the power supply.
- Next, carefully pull out the display panel of the thermostat from its base.
- Assess whether there are any protruding cables. If so, tuck them back into the wall safely. Ensure all the wires and cables are attached properly to the wall.
- Carefully arrange the base connectors and plug them into the base of the thermostat.
- Finally, press down the display on the base until you hear the display producing a clicking sound. Ensure that the panel has been properly attached.
Reason 5: Incompatibility issues
A Nest thermostat that is incompatible with your HVAC system may lead to major issues that require expensive repairs.
Incompatibility issues occur in several ways. Sometimes, you bought a second-hand Nest thermostat, and you didn’t check whether it supports your HVAC systems.
Sometimes, you recently performed a repair or maintenance in your HVAC systems and added some incompatible parts.
Or, your thermostat is just incompatible with your cooling and heating systems.
Nest thermostats are normally compatible with most low-voltage, 24-volt residential heating and cooling systems.
Using high-voltage HVAC systems (like electric baseboard heaters) can damage your Nest thermostat.
Nest thermostats are incompatible with other HVAC systems like millivolt heating systems (e.g., floor heaters or wall heaters) and proprietary heating systems (non-standard wire labels). If you use any of these heating systems with your Nest, the thermostat may not get adequate power to charge its battery.
Apart from high voltage, millivolt, and proprietary heating systems, other heating systems function properly with Nest thermostats.
Incompatibility within the HVAC system normally prevents the thermostat from functioning properly, leading to the screen going blank.
Your HVAC needs to operate as a complete system. So if you’ve recently replaced a component (like a furnace, condenser coil (outside), evaporator (inside), or another part), and one of them isn’t working properly with the rest of the system, it can cause problems in the entire system.
How to fix: Call an expert
To resolve the incompatibility issue:
- Ensure your Nest thermostat model suits your HVAC system.
- Call a certified HVAC professional to replace the incompatible parts in your heating and cooling system.
- When installing the Nest thermostat, you should call a certified HVAC professional to help determine the nature of your heating system and whether it’s compatible with the thermostat.
Reason 6: Damaged thermostat
After you’ve tried all the above troubleshooting solutions and your Nest thermostat still blanks, it means the device is defective.
Chances are that your thermostat is old, worn, or damaged.
Most thermostats can last 10 years or more. But the overall lifespan depends on many factors, like the quality of the unit, the nature of usage, and others.
How to fix: Replace the thermostat
- If you feel that your thermostat is defective or old, consider a replacement.
- But before that, contact an HVAC professional to assess the device and rule out other issues, like wiring problems, circuit issues, etc.
- If the professional can’t figure out another cause for the blank screen, then consider replacing the thermostat with a new model.
My Final Thoguhts
A Nest thermostat can do a lot for you, from making life more convenient and increasing your home’s comfort level, to helping you save energy and money.
However, every thermostat out there has the potential to misbehave due to technology issues.
With this article, you can resolve the blank screen on your Nest thermostat before needing to call for help.