How to Fix a Blank Thermostat

The temperature in your home feels a bit uncomfortable so you walk to your thermostat for an adjustment. But when you get there, the screen is blank. 

If you’re puzzled by a blank thermostat, we’re here to help you fix it.

Causes of a Blank Thermostat

A blank thermostat can be caused by a couple of different things. One cause could be a faulty screen, which is typically evident when your HVAC system is running smoothly but the thermostat screen is blank. 

Another cause could be a power failure, which will usually be obvious and cause your system to shut down and not turn back on.

But perhaps the most common cause for a blank thermostat screen is actually just a clogged drain. 

How Does a Clogged Drain Cause the Thermostat to Go Blank?

Your HVAC system pulls moisture from the air inside your home, and some of it condenses into water and collects in a drain pan that is then routed outside the home. 

The drain can become clogged with algae and debris if not properly maintained. And when this happens, the water gets backed up and the level rises which in turn activates the overflow safety switch that kills the power and causes your thermostat to go blank.  

How to Fix a Clogged Drain and Restore Your Thermostat

The first thing to do is remove the standing water in your drain pan using a shop-vac. Once enough water is removed and the water level drops, power should be restored to your thermostat. 

Then take the shop-vac outside the home where the water drains out of a pvc pipe and use the shop-vac to remove water and debris from the pipe. You will likely see a rush of backed up water come out of the pipe once the shop-vac loosens the clog. This should restore proper function to your HVAC system. 

What If the Thermostat Is Still Blank?

If your thermostat is still blank or the HVAC system is not working properly after unclogging the drain, there may be another issue and it might be time to call in a professional for help. We offer HVAC repair and maintenance and have been serving the Wilmington, NC area for more than 10 years.

Book your service appointment online and our expert technicians will get your thermostat and HVAC system working like new again.