What Are the Most Common Hot Air Furnace Repairs?

Just like your car or truck, your hot air furnace is a hard-working machine with a lot of moving parts that requires a regular maintenance schedule. American Airflow offers our Comfort Care members a complimentary tune-up on their heating system every year. Regular maintenance will expand the life of your equipment and minimize costly repairs over time, but of course, parts eventually wear out and must be replaced. 

hot air furnace replacement

Common Hot Air Furnace Repairs

  • Flame Sensor
  • Hot Surface Ignitor
  • Blower Motor
  • Run Capacitor
  • Gas Valve
  • Pressure Switch
  • Inducer Motor
  • Thermostat
  • Air Filter

Here are the most common repairs we perform for our customers with a hot air furnace. 

Flame Sensor

The flame sensor generates a voltage when the flame of the burner makes contact with it. If this sensor does not generate enough voltage, the control board will recognize that there is no flame present and turn off the gas valve causing the furnace to be non-functional. 

Hot Surface Ignitor

The hot surface ignitor is used during the startup of the furnace and glows bright and hot to ignite the gas from the gas valve. If this device does not heat up, the ignition sequence will fail to render the furnace non-functional. 

Blower Motor

The air that moves through your home is generated by the blower motor inside the furnace. This motor runs whenever the heat or air conditioning is on and in some cases 24 hours per day, so they do wear out eventually.

Run Capacitor

The failure of a run capacitor is a common repair item that can be caused by high heat, constant on and off of the equipment, voltage imbalances, or simple wear and tear over time.  

Gas Valve

The gas valve is what opens to provide gas to the burners which in turn produces the heat within the home. If this valve should fail, the unit will not produce heat. Upon completion of the replacement, a combustion analysis is performed to ensure safe burner operation.

Pressure Switch

When a furnace comes on it is important to make sure that the flue product created by the burning gas is properly vented from the home. The pressure switch is a safety device that will not allow the furnace to operate if the venting system is plugged or if the venting motor is not operating. 

Inducer Motor

The inducer fan motor assembly pulls the products of combustion across the heat exchanger and expels them into the flue pipe which runs to your chimney. If this inducer motor assembly does not operate, the burner will not fire resulting in no heat.


A thermostat is a component which senses the temperature of a physical area and performs actions so that the room’s temperature is maintained near a desired setpoint. It exerts control by switching heating or cooling devices on or off to maintain the correct temperature.

Air Filter

HVAC units with dirty air filters can be a concern in any residential environment. This can cause the HVAC unit to work harder than it should and can keep the same dust and pollen circulating in the air we breathe.

System Replacement

Just like with your automobile engine, more parts will begin to fail as your furnace gets older. The issues we have listed here are normal wear and tear, which as you know is simply a part of an aging machine. That being said, please keep an eye on the number of repairs as your system matures. If repairs begin to occur more often and you find yourself spending an increasing amount of money, it might be time to discuss a potential replacement with your HVAC contractor. 

Frequently Asked Questions (FAQ’s)!

What are the most common hot air furnace repairs?

The most common repairs performed during the winter months on American Airflow customers with a hot air furnace are the flame sensor, hot surface ignitor, blower motor, run capacitor, gas valve, pressure switch, inducer motor, thermostat, and air filter. These parts fail due to normal wear and tear so do not be surprised if your furnace requires service from time to time in order to function at its best. 

When is it time to replace my hot air furnace? 

The standard lifespan for a hot air furnace is 15-18 years, which is obviously a wide range. We encourage our customers to allow us to perform minor repairs on an aging system to the point where it is cost-effective. Once the repairs begin to add up to nearly the cost of a new machine, then it is time to discuss a replacement. 

Why are HVAC repairs so expensive? 

Most importantly, your local HVAC company is paying knowledgable technicians with necessary diagnostic skills who work in dangerous conditions. Other expenses that are factored in are gas, driving, inventory, paperwork, licenses, insurance, training, plus unplanned – and often complimentary! – return visits. Typically, HVAC companies charge a flat rate for services and repairs, which can be greatly beneficial to the customer because the fee is the same whether it takes the technician two, three, or four hours. 

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