Why Does My Aprilaire Thermostat Say Off? (Must Read)

By - Ron Singh

Updated -

Aprilaire thermostat offers their customers an additional advantage in that they make it easier to supervise the air quality of your house, the humidity status, and the smell of your room.

With the Aprilaire thermostat, you can eradicate pollutants in your house. But sometimes your Aprilaire may show some errors or not turn on and might be of serious concern to you, especially when your thermostat is off.

Aprilaire thermostat controls your heating system. It regulates the system to fit the room temperature and is very simple. Your Aprilaire thermostat will not turn on if the battery is low or if there is a faulty circuit breaker.

Why Does My Aprilaire Thermostat Indicate That It Is Off?

Why Does My Aprilaire Thermostat Say Off

 If you don’t turn on your power switch, your Aprilaire will not work. After turning on the power button and the thermostat is blank, the thermostat has other problems.

The common problems with a blank thermostat include the following;

  • When a circuit breaker trips, it turns off your thermostat power, clearing the screen.
  • A blank thermostat screen might indicate a low battery. It would be best if you replaced some batteries once a year.
  • Furthermore, loose connections and faulty wiring can stop your Aprilaire from turning on.

Also, when your Aprilaire is off, it might be because the safety switch is activated.

Sometimes, an air conditioner or furnace will activate the safety switch and turn off the thermostat completely when it detects any harm.

The air conditioner activates the switch when water flows excessively in the condensate pan.

In contrast, the furnace initiates the safety switch when the unit is excessively hot and dangerous.

If none of the problems above cause your blank thermostat, you need to buy a new one. The average lifespan of a thermostat is ten years.

How to Turn on the Aprilaire Thermostat?

To turn on the Aprilaire thermostat, press the power switch and start your operation. To select your system, press Mode. It will give you the following options:

Auto: When you press this option, the thermostat will choose the heating or cooling temperature that will fit the indoor temperatures. It can also help you switch between the heat and cold settings.

Off: By pressing this option, you will turn off the heating and cooling system. Heat: The heat mode will enable the thermostat to control just the heating system.

Cool: The cool mode monitors only the cooling system. Em-heat: This mode allows the thermostat to control just emergency or auxiliary heat. When this mode is on, the heat pump will not work.

Aprilaire Thermostat Troubleshooting

The Aprilaire thermostat may show errors or stop working without you knowing the cause.

If you experience this issue, do not panic. Below are some Aprilaire problems and how to troubleshoot them.

If the display goes blank, check the circuit breaker and replace it if it’s old. When the thermostat says low battery when you turn it on, switch it off and change the battery.

Next, Switch on the power button if off. Then shut the thermostat furnace door firmly.

If  Aprilaire produces insufficient cold or heat, Switch on the heat or cold mode when turned off; here’s what to do.

If you want more heat in your room, raise the temperature above 72°F. However, if you want your room to be cold, set the temperature below 72°F. 

Check the thermostat’s electrical connections and repair any loose connections. Contact the manufacturers if you need to service or repair your Aprilaire’s inner heating system.

To resolve a situation of your fan not working, check the fan’s wiring. If you notice a short or the thermostat fan wires are brushing, change the wires and separate the touching wires. 

Turn on the fan if it is off. If you notice the problem is from the fan’s inner system, it’s best to call a professional to fix it. 

If the furnace or cooling cycles are short, ensure the size and the location of the thermostat heating or cooling system is suitable for your room. If not, call the local assistant to adjust the thermostat size or location.

How Do You Check a Thermostat Battery?

Most thermostats use batteries, while others obtain their power from home appliances.

Modern thermostats will alert you when the battery level is low, but you can manually check the battery level.

To check the battery level, adhere to the following steps;

  • Go to the Menu view and click on Settings. 
  • Then click on the battery icon. You will see the battery status. 
  • If the battery is low, it’s best to change it to a new one.

Another way to know when the battery is low is the low battery indicator.

This indicator might be in the form of a warning text, flashing light, or a low battery symbol that will go on for about a month or two before your thermostat battery drains completely.

When the thermostat battery drains completely, except the following problems:

  • The thermostat display will be blank, and all the data you program on it will erase. Your data is safe when you connect the thermostat to your house grid system.
  • Your home may become uncomfortable to stay in when the thermostat battery dies. Since the thermostat cannot provide capacity to the HVAC system, your house may become too hot or too cold to stay.
  • The thermostat will not react to your voice commands when the battery dies.
  • If your thermostat operates fully on your home grid, it might begin to malfunction since there is insufficient power for the thermostat. It might even begin making weird noises or continuously turning on and off.

If you experience any of these problems with your thermostat, it’s advisable to change the battery.

#1. How to Change a Thermostat Battery?

Before changing the thermostat battery to a new one, grab a few tools like a short one-foot level and a set of screwdrivers and follow the following steps:

#1. Step 1:

Switch off the thermostat.

#2. Step 2:

Gently remove the thermostat covering from the wall mount plate. If you find it hard to remove, push it up gently and pull it off the wall mount.

#3. Step 3:

Check the end of the thermostat to know the type of battery it is using and turn it over to replace the new battery.

Some thermostat batteries are easy to remove, while for others, you must use a screwdriver to pull the battery slot out.

#4. Step 4:

After removing the old batteries, put the new ones into the slot. The positive terminal of the batteries must face up unless the thermostat cover says otherwise.

#5. Step 5:

Connect the positive and negative indications on the label with the battery.

#6. Step 6:

Fix the thermostat house gently to the wall plate. Now you can turn in your thermostat to see if it’s working.

If your thermostat battery contains mercury, be careful when fixing it. Mercury consists of neurotoxin that is harmful to the body. Therefore, ensure you dispose of it properly.

The best batteries for your thermostat are AA alkaline battery, AAA alkaline battery, and 3V disc-style lithium battery. 

#2. AA Alkaline Battery

This most common thermostat battery has two electrodes and a metal named anode. The anode has a negative charge, while the cathode has a positive charge.

The AA battery transmits power to the thermostat and enables backup when there is a power failure. 

#3. AAA Alkaline Battery

This battery is also called a triple-A battery. It is an alkaline battery with a small size and a low voltage.

This battery is suitable for thermostats because it is easy to remove and fix. This battery is stronger than a zinc battery and lasts longer, but you cannot recharge the battery.

#4. 3V Disc-style Lithium Battery

The 3V lithium battery is another battery used in a thermostat. The battery has a voltage of 3 Volts, and it is durable.

This battery only conserves 70% to 80% of its energy, and you use it with the thermostat detector and controller board. 

Due to its low voltage, you can use it to power a thermostat. A thermostat needs steady power, which the 3V disc battery can conserve. Although the lithium battery lasts long, the voltage reduces rapidly.

How Do I Reset My Aprilaire Thermostat?

The thermostat obtains its power through AC or the battery. The reset button is under the battery cover. Just press it to reset your thermostat to the factory setting. 

When the thermostat gets its power from AC, it comes with an optional battery that only supplies backup power to the clock.

The thermostat comes with a memory backup that stores the settings even when there is a power failure while resetting.


Aprilaire thermostat is a reliable device that makes it easier to maintain your house temperature. So if your Aprilaire says off, turn on your power switch. 

But if your thermostat refuses to work, check for other problems. You can also call a professional to check and help you fix your thermostat.

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