One of the key components of your HVAC system is the thermostat. While thermostats are generally considered to be very reliable, if a problem does occur, you will find that you cannot control your heater or air conditioner. For example, if you want to turn on the air conditioning as the temperatures increase only to find that the digital thermostat screen is completely blank. This would mean that you can’t get any of the commands to respond, and you will be sat in the heat until you can solve the problem. Fortunately, there are common reasons for the underlying issue, which means that you may be able to correct yourself without needing to call in a professional HVAC specialist.
A digital thermostat can be powered by either a direct electrical system connection or batteries. When your thermostat is powered by batteries, a blank screen is likely to be a result of the batteries going dead. If you remove the thermostat front plate from the wall, you will see the battery compartment, enabling you to try fresh batteries and see if it resolves the issue.
Your Circuit Breaker Has Been Tripped:
Another common reason for a blank digital thermostat screen is that the circuit breaker has been tripped. Have a look at your electrical panel and check to see if any breakers need to be reset. Once this is done, check if the display has returned to normal.
The Limit Switch Has Tripped:
Most air conditioners have a limit switch, which is designed to shut off the unit’s power supply should the condenser pan become flooded. The limit switch may also shut off the power supplied to the thermostat. There are other conditions, which may trigger the limit switch and cause your digital thermostat screen to go blank, including the furnace overheating or clogged filters restricting airflow. Before you can restore normal function to both the system and your thermostat screen, you will need to determine why the limit switch has tripped and correct the underlying issue.
When your digital thermostat is wired into the electrical system of your home, loose connections and bad wiring can also cause the screen to go blank. If you have experienced wiring issues in the past, it is worth considering whether this is the reason for your thermostat issues. A professional technician will be able to check the wiring, and it could save you needing to replace the unit with a new thermostat.
Although a blank digital thermostat screen can be frustrating, in many cases there is often a quick fix. A set of fresh batteries or a check of your electrical panel may immediately solve the problem. If you are still struggling, it is important that you check with a professional HVAC technician. A blank screen could be symptomatic of a serious underlying fault, so it is important that you not use the equipment and have it checked as soon as possible to ensure that it is safe.