Mar 23, 2020

Thermostat issues can be difficult to manage, as they may be signs of the smallest possible needed care to large HVAC problems. Last year, the experts at Newcomb and Company covered the basics of blank thermostat screens. With new developments in the world of thermostats, we are here with additional insight into why your thermostat may have a blank screen and what you can do about it.

Problem: Breaker trip

Breaker trips can cause all kinds of panic when an area of electrical functions in your home stop working. This includes your thermostat. If your breaker trips, your system may be switched on, but it will not have any power running to it, causing a blank screen.


Check your breaker box and see if the breaker to your HVAC or thermostat is tripped. If so, simply switch it back and check your thermostat to see if your screen has come back on.

Problem: Batteries are dead

Do you have a battery-operated thermostat? This is perhaps the easiest problem to fix—your system may simply have dead batteries that need to be replaced.


For those who feel comfortable and confident in your ability to safely replace your batteries, check to see if a new set will bring your thermostat back to life. If you are not able to successfully change your batteries on your own, consult a local expert for help.

Problem: Wiring, electrical, or fuse issue


If your thermostat runs off of electricity, this could be a sign of a wiring issue. Loose or faulting wiring might be the culprit, especially if your thermostat is newly installed. This may also occur if you recently wired your system to convert from a battery-powered thermostat to an electrical thermostat. Burnt out wiring and blown fuses are common if your system was connected to a higher voltage than what it was designed to manage.

Solution: Expert care

An HVAC expert will inspect the wiring to your thermostat and see what kind of damage has been done. They will properly configure the system to meet the proper electrical requirements. This includes fuse replacements, wiring modifications, and system care. If your entire system has incurred damage, it may need to be replaced.

Problem: HVAC power

You may treat your thermostat as the on/off power switch for your HVAC system. However, your system may also have a separate on/off switch or a breaker power switch. If your HVAC power is shut off, your thermostat may also shut off accordingly.


Make sure your HVAC system is turned on. Find the core power source for your unit. It may be in a covered box outdoors or somewhere near your unit. If you find it is turned off, switch it on and check to see if your thermostat function is restored.

Problem: HVAC issue

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An HVAC expert can complete diagnostics to find the source of your issue. You can then begin the repair or replacement options best for you and your system.

Problem: Programmable or remote-controlled settings

Programmable and device-controlled thermostats are remarkable when used properly. However, those less technologically adept might have accidentally mismanaged the system. While your thermostat screen should still turn on in-person, there is a chance you may have disabled certain settings or controls.


There are a few different approaches you can take here. First, if your system is connected to a digital assistant like the Google Home Hub, simply ask your device to adjust the temperature settings. This should kick your system’s functionality back on. You may also consider checking and adjusting the settings within your application.

Problem: Furnace door is open

If your thermostat is reading blank, it could be a sign that your furnace is open. This problem is especially common among Honeywell thermostats.


While it may seem like an unrelated issue, an expert can inspect your furnace and furnace door to ensure that they are properly configured. Securely shutting the furnace door can, in these instances, return power to your thermostat.

Problem: Power-saving mode

If your unit has been off for any period of time, it might enter energy-saving mode. This is not a problem at all, but rather a way for your unit to save power. It is common for your thermostat to enter power-saving mode on its own, so do not be concerned if you notice this is something you did not set yourself.


Every thermostat is different, but your system should quickly come back to life at the touch of any button after entering power-saving mode. If that does not work, you may try turning your thermostat off and back on again or completing a full reset. If none of these options bring your thermostat back to life, you likely have a different issue within your system.

Problem: Tripped Float Switch

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Your AC drip pan is designed to catch excess water produced by your air conditioner before it is released by your condensate drain. Your drain pan is not supposed to hold standing water for extended periods of time; instead, your system is supposed to drain this water soon after it is produced. Excess water can hurt your system, which is where the float switch comes in. This system shuts off your HVAC when it detects an issue with your drain pan.


The issue here is not with the drain pan or your thermostat, but rather with the condensate drain system as a whole. There is likely a clog that is preventing your system from properly draining. Once the clog is removed and the system drains, your thermostat should resume its proper functioning.

Problem: Tripped high-limit switch

The high-limit switch is designed to trip when your system begins to overheat. Restricted airflow, a struggling motor, or another issue within your HVAC system can force it to overwork and overheat. This could be caused by dirty clogged air filters, dirty HVAC system parts, or pieces of your system that have reached the end of their lifespan.


The solution here has less to do with the thermostat problem and more to do with the HVAC issue that is causing it to overheat. HVAC maintenance can keep your system clean, which prevents these issues. It also helps restore function to your unit if you have waited an extended period of time between maintenance visits. Your HVAC expert will also replace any broken parts, detecting issues early before they create larger problems. However, with the right cleaning and care, your parts will not experience as many problems. Once your unit is properly cleaned and in good working order, your thermostat function will return.

Problem: System turned off

This problem is so obvious that it is easy to miss—your thermostat may simply be turned off. Depending on your system, the light may stay on while turned off. It might also stay on at first and enter power-saving mode later, creating confusion when your thermostat screen reads blank.


Find the power switch to your unit and make sure it is turned on. If the screen is still blank after you turn it on, you are likely facing an additional problem with your system.

Problem: Dimmed lights

Your thermostat screen might be turned on and functioning properly. You may simply not be able to see the display due to dimmed lighting.


For some systems, this could be signs of a dying battery in power-saving mode. For newer thermostats, this could be a setting you can change. While it might be difficult to see the settings screen with the lights dimmed, bringing it to a low-light area can help. If you do not have display light settings in your system, this could also be an older thermostat losing its life.

Problem: Old, ineffective thermostat


If your system is older, you might simply be encountering a dying thermostat. The display light may be dead or broken. There may also be another internal element of your thermostat that has simply given out.


A new thermostat can be connected to your system for improved and accessible functionality. An expert can help you find the new thermostat that works for you and get it installed in no time.

Newcomb and Company Thermostat Repair

Newcomb and Company was voted the best HVAC company in the Triangle. Who better to call for your thermostat and HVAC repair needs? We proudly serve Wilmington, Raleigh, and surrounding areas. Schedule an appointment with our experts today for all of your home or business thermostat needs.

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