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What You Should Do if Your Furnace Turns On and Off Again

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What steps can you take if your furnace turns on and off again? In this situation, you can review the causes for this type of furnace malfunction. You also have the opportunity to get professional help with repairs. 

Learn more about HVAC installation and repair in Evansville, WI, by contacting our team at Rock Valley HVAC. You can reach us when you call 608-247-4949.

furnace turns on and off

What Happens When Your Furnace Turns On and Off?

Furnaces should run until the heating system brings your home or business to the proper temperature. The heating system should then turn off and remain off until the temperature drops by a degree inside your property. 

However, in some situations, a furnace begins to operate for only a few moments at a time. Your furnace may stop running before it increases the temperature in your home, only to kick on again a few minutes later.

 You may want to contact a professional HVAC team if you notice this happening. Note that your furnace should turn off after changing the temperature, so this does not represent a cause for concern. 

Determine Why Your Furnace Cycles On and Off

The first step to handling a furnace that continually cycles on and off involves assessing the root cause of the problem. The most common reasons for a furnace to begin short cycling include:

Dirty or Clogged Air Filters

When your furnace runs, it circulates air through your ventilation system. The air ends up passing through a filter to remove contaminants like:

  • Dust
  • Pet dander
  • Pollen 
  • Dirt 

Over time, the filters grow clogged with debris taken out of the air. Clogged filters prevent your furnace from getting necessary airflow, often causing your system to overheat and stop running early. You can avoid this problem by regularly changing the furnace filters. 

Other issues may also cause low airflow to your furnace. Ensure that all the air supply vents in your property are open and clear to allow air to get back to the heat exchanger. You may also encounter issues if your blower wheel gets dirty.

Changing your air filters every few months helps prevent the accumulation of dirt on the blower wheel. 

Issues with Your Thermostat

The thermostat controls the operation of your heating system. You enter the temperature you want on the thermostat, and then it sends commands to the furnace. Therefore, sometimes furnaces turn on and off repeatedly due to malfunctioning thermostats.

Thermostat issues often occur if:

  • The thermostat needs new batteries
  • You have a thermostat with old and faulty wiring
  • Builders placed the thermostat in a bad location 

You can change the batteries in the thermostat yourself to see if it resolves the issue. However, you should always work with the professionals if you believe you have a wiring issue. 

Finally, what does it mean for your thermostat to be in a bad location? Thermostats placed near outside walls or close to windows often experience different heat levels than the rest of your house, causing them to activate the furnace at inappropriate times.

An HVAC professional can relocate your thermostat if your furnace turns on and off again improperly. 

Your Furnace Is Too Big

Sometimes, people end up with an oversized furnace for their homes. Unfortunately, large furnaces often end up short cycling because they heat parts of the house too quickly and then turn off. 

Fixing this problem requires replacing your furnace with an appropriately sized model. You can turn to furnace installation crews to quickly get a new furnace for your property. 

A Problem with the Flame Sensor

Flame sensors play an essential role in the safe operation of your furnace. These sensors shut down your gas valve if they do not detect a flame in the furnace, because operating a furnace without a flame can allow dangerous gas into your home.

However, sometimes these sensors become dirty or corrode. These issues prevent the sensors from detecting a flame, making the system think there’s a problem. 

An HVAC technician can clean your flame sensor in this situation, getting your furnace working correctly again.

A Clogged Flue Pipe

Most furnaces have a flue pipe (or exhaust vent). The vent allows hot gasses produced by the furnace to escape your home. Unfortunately, these pipes often get clogged by debris such as sticks, dirt, and leaves. Clogs may cause your system to overheat and shut down. 

Working with a furnace maintenance crew can prevent this issue. Technicians ensure the flue pipe stays clean by removing buildup before it causes a clog. 

Problems with the Blower Motor

Your furnace or air conditioning system circulates air through the use of a blower motor. Generally, a furnace simply will not operate with a broken blower motor. However, sometimes your furnace will still heat the air without circulating it.

If you have weak airflow – or no airflow – through the vents on your property, you may have a problem with your blower motor. Allow a furnace repair specialist to help you address this issue by fixing or replacing the blower motor. 

The Furnace Is Overheating

Finally, your furnace may overheat due to component failures or a breakdown. If your furnace begins to overheat, safety features cause the system to shut down early to prevent a fire or increased damage to the heating system.

However, allowing your furnace to overheat repeatedly often leads to more severe problems. Contacting a furnace repair crew allows the professionals to assess the cause of your issues and to begin repairs quickly. 

Steps to Take if Your Furnace Turns On and Off

How should you react if your furnace turns on and off? First of all, turn the heating system off, just in case you’re dealing with an overheating issue. Once you have the system off, you can perform a few checks on your own.

Check the batteries on your thermostat and see if that fixes your issue. You can also look at the air filters and change them with a clean replacement. If the furnace continues to switch on and off with fresh batteries, reach out to a professional furnace repair company in Evansville. 

HVAC professionals understand how furnaces function. They’ll reach your property quickly and assess the issue, checking the blower motor, flame sensor, flue pipe, and more. 

Technicians provide you with information about the problem before they begin repairs. Sometimes, they just need to clean a sensor or replace a part in some situations. However, if your furnace is too big for your home, they may suggest replacing the system. 

How to Keep Your Furnace in Optimum Condition

Ideally, your furnace will run properly and kick off at the proper time. You can keep your furnace operating correctly by setting up regular maintenance appointments. HVAC technicians clean furnace components, change filters, and check all electrical connections during these appointments. 

The experts generally advise you to set up a maintenance appointment in the fall to check on the status of your furnace. However, you can schedule the appointment whenever it works best for you. 

Contact Us if Your Furnace Turns On and Off Again

You have options if your furnace turns on and off. You can reach out to the professionals at Rock Valley HVAC to get help right away. We provide repair services as well as maintenance appointments in Evansville, WI. 

Learn about the most common reasons for furnace failure and how we can resolve the issue by calling us at 608-247-4949.