What To Do When Your Furnace Blower Won’t Turn Off

A furnace is a popular system designed to help warm indoor spaces during the cold season. Many Americans across the US use a furnace, and while there are different fuel types, all furnaces have a similar heating process.

A furnace first draws in cold outdoor air using the blower fan, and this air is then blown to the burner, which heats it up. Next, the blower fan blows the hot air into the ductwork, distributing the warm air to each room in the house.

The blower motor is a component that helps the blower fan run when the furnace is heating the air. Typically, when the house is warmed up and meets the thermostat settings, the furnace turns off, and so should the blower fan. 

Your furnace blower should not run continuously. If it does, it could indicate a problem with other components of your system, such as the thermostat, air filter, ductwork, or limit switch. Read below for tips on what you can do. 

What to do when your furnace blower won’t turn off

If your furnace blower won’t turn off and you don’t know what to do, here are some steps you can take to fix it. 

  1. Check the thermostat settings

One reason why your furnace blower won’t turn off is because of incorrect thermostat settings. For instance, the blower will continue blowing if the settings are higher than what your furnace can achieve. This is because it will continuously heat the space in an attempt to reach the set temperature.

So, before you assume it’s an issue with the blower itself, check the settings on your thermostat. You may need to set it to the right temperature, and your blower will adjust in no time. You should note that the wrong thermostat settings might also mean your furnace won’t go off either.

  1. Check the limit switch

If your settings are okay, the next step is to check the air temperature. If the air being blown into the house is cool, you will want to check the limit switch, as this might be the culprit.

With a limit switch, you may face either of these two issues: the fan setting is set to “ON” or “Manual,” or the limit switch itself is broken. If the switch is on the wrong setting, change it to “Auto,” and the blower should return to normal. 

If you change the settings to “Auto” and nothing happens, you might be dealing with a broken limit switch. While changing the settings is something you can do yourself, a broken limit switch will require the help of a professional HVAC technician. 

  1. Check the air filter

Every HVAC unit has an air filter that helps to filter off the dust, dirt, and other particles before they reach indoors. Your furnace air filter should be cleaned or replaced regularly, as recommended by the manufacturer, to ensure that your system can function properly.

If the air filter gets dirty or clogged with dirt and particles, it will prevent enough air from passing through. Compromised airflow means that the furnace won’t be able to heat your indoors effectively. As a result, it will continue running and put a strain on the blower as it tries to maintain the set indoor temperature.

So, if your furnace won’t turn off, a dirty air filter might be the cause. And as long as the furnace is running, the furnace blower motor won’t turn off either.

Many homeowners clean and change the air filters themselves, but if you’re having trouble, don’t hesitate to call a professional to help you. 

  1. Check for wiring issues

Wiring issues could also be the reason your furnace blower won’t turn off. Aging or faulty wiring in the system can bring problems to your motor, causing it to malfunction. For instance, if the wires come into contact with one another, it can cause your unit to short-circuit.

There are two main places where this can happen: in the thermostat or the limit switch. So, if none of the above-mentioned issues are the problem, check if the wiring is okay and ensure wires aren’t touching where they shouldn’t.

Be careful since wires deal with electricity and can pose a risk to your safety and your household. Therefore, this should be left to licensed professionals – unless you are one yourself.  

Help! My furnace won’t turn off. What should I do? 

Just like a blower motor, your furnace shouldn’t run non-stop either. It should only run when it’s heating and go off when it reaches the desired temperature set by the thermostat.

We often get questions from homeowners like, “why won’t my furnace turn off?” If you’re having trouble with an ongoing furnace, here are some common reasons why.

As we mentioned earlier, always check your thermostat first. This small device is the brain of the entire HVAC system; an issue with your thermostat will affect the whole system. 

Also, if the settings on the thermostat are wrong, the furnace might continue running as it tries to achieve a particular indoor climate. Always check that your thermostat is functioning properly and has the correct readings.

Other issues that might keep your furnace running may include the following:

  • Wrong wiring
  • A faulty blower motor
  • Leaky ductwork
  • A faulty compressor contractor
  • A dirty or clogged air filter

These issues can easily cause your furnace to malfunction or run continuously. Always seek help from an expert to ensure that the right diagnosis is made on your system and that the proper solution is offered.

Is your furnace causing issues? Let Anderson Air help. 

A furnace ensures that your indoors are comfortable during the cold season. If it malfunctions, it’s easy to panic and wonder how you’ll survive those winter days. 

Fortunately, even though a furnace can break down, it can be restored to optimal condition with some quick fixes. This, however, will require the assistance of a qualified technician. Don’t run the risk of causing further damage to your system.

At Anderson Air, our professional technicians have years of experience and will be ready to help you with any of your HVAC needs. Schedule an appointment with a qualified technician today. 

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