Why Is My Thermostat Blank?

It is an “Oh no!” moment when you approach your home’s thermostat and see its blank screen.

Is this a serious issue—does it mean your furnace, heat pump, or air conditioning is broken? Not necessarily. In fact, most of the time, it is something minor and can be easily fixed!

We’ll cover some of the most frequent reasons our Divine Heating and Cooling professionals see a thermostat blank screen here in the Oregon, area.

Why a Thermostat Goes Blank

Wondering why your thermostat suddenly went blank? It’s a common issue that can leave you without heating or cooling when you need it most. Let’s explore the most likely reasons behind a blank thermostat display—and how to fix the problem fast.

The Thermostat Has Dead Batteries

If your thermostat wall does not have a C-wire or common wire, your thermostat is most likely not hooked up to your heating, ventilation, and air conditioning (HVAC) system for its power and requires batteries. When your screen is blank, it could indicate that you need to replace the batteries.

If this is the case, you typically need AA alkaline or 3-volt lithium batteries, so check what type is currently powering the thermostat and simply replace them. Most thermostats display a low-battery symbol when the juice is running low.

On the other hand, if your thermostat is hardwired to your HVAC system for power, it could be a temporary blank screen if the thermostat is in the middle of recharging. Wait a short time and see if the display returns. If it does not, read on.

Loose Wiring or Wiring Problems With Your Thermostat

Sometimes the wires hooked up to your thermostat are responsible for its lack of power. If they originally were not firmly attached or the thermostat is in a high-traffic room, the vibrations from people walking by can actually affect the wires.

Our professionals have also seen wires chewed by rodents damage the wiring. These rodents will continue to cause havoc in your Portland, home until you locate their entrance/exit opening and permanently seal it to help rid your property of their infestation.

Since wiring deals directly with electricity, we recommend calling us to diagnose and repair the issue for you. When it comes to electricity, rely on a professional. It is much better to be safe than sorry.

Thermostat Has a Tripped Circuit Breaker or Blown Fuse

Sometimes, a power surge or outage can cause this issue.

It is a quick fix to restore your thermostat’s power if it is caused by a tripped circuit breaker or blown fuse, depending on what you have in your Oregon home. If you check your electrical box and a circuit breaker is tripped, just flip it back. If you have fuses, replace the fuse.

Once this is done, check your thermostat. If you have power again, you are set, but if the breaker trips again or the replacement fuse blows, you may have a more involved HVAC problem. You need to get one of our Divine Heating and Cooling professionals involved.

Thermostat Has a Tripped Safety Switch

Your HVAC system includes built-in safety switches designed to shut things down in potentially unsafe conditions. When a safety switch is triggered, it can cut power to your system’s transformer—stopping power to your unit and possibly your thermostat.

If you have a furnace, contact our HVAC professionals for proper diagnosis and repair. If you’re using a heat pump or air conditioner, check the condensate pan. If it’s full, the safety switch may have tripped to prevent overflow. If the pan is full, call us for assistance.

Open Furnace Door Can Power Off a Thermostat

Every once in a while, our team members come across an open furnace door that causes a blank thermostat. Some thermostats are more sensitive to this issue than others, but it is worth checking.

If your furnace door is not closed tightly, your thermostat may turn off. Simply closing the door securely should restore power in this situation.

Your Thermostat Is Old

Though thermostats can last 10 to 20 years, they do wear out. Unfortunately, if your thermostat is older, this may be the problem. Sometimes it is just time to replace it.

Be sure to have one of our HVAC professionals install a new one. Programming newer, smart models can be complicated, and you want to avoid issues with it in the future.

Call Divine Heating and Cooling With Any Thermostat Concerns

At Divine Heating and Cooling, we frequently field phone calls in Portland, OR, regarding thermostat issues. If your thermostat has a blank display, try the ideas mentioned above to see if you can restore its power. But if they are not solving your problem, or if you are hesitant about attempting these on your own, please call us at 503-420-8059 or request service online. We are happy to help.