Furnace Inducer Motor Troubleshooting: Signs, Causes, and Fixes

When it comes to your family’s safety, furnace inducer motor troubleshooting is essential. This motor is responsible for pushing combustion gases out of your home. If it isn’t functioning, your furnace will automatically shut down to prevent safety issues.

What Does a Furnace Inducer Motor Do?

A furnace inducer plays an integral role in your furnace and protects your family from combustion byproducts.

How It Supports Combustion and Venting

As a part of your heating, ventilation, and air conditioning (HVAC) system, the inducer motor is responsible for pulling air through your heat exchanger. Then, this air is vented outdoors. By creating a negative pressure, the motor ensures combustion byproducts are safely vented outside.

Why the Pressure Switch Depends on It

Your furnace has a pressure switch that detects the inducer motor’s negative air pressure. If it doesn’t detect the right pressure level, the switch will trigger your control board to shut everything down.

Signs of a Bad Furnace Inducer Motor

You may have a faulty furnace inducer motor if you notice the following symptoms.

• Furnace Will Not Start: If the inducer motor doesn’t function, it can’t create enough draft for ignition.
• Humming, Grinding, or Rattling Noises: An unbalanced fan or motor can cause rattling noises. Grinding and humming sounds often stem from worn bearings or faulty internal components.
• Intermittent Heating Cycles: A lack of airflow and pressure can cause short cycling.
• Error Codes or Lockouts: System lockouts will occur as a safety mechanism. Often, there will be error codes as well.
• Burning Smell or Overheating: If the motor is seizing or the windings are failing, your furnace may overheat. It can also produce burning odors.

Common Causes of Inducer Motor Problems

There are a few common reasons for inducer motor malfunctions.

• Worn Motor Bearings: If the motor bearings aren’t properly lubricated, it can cause your system to lock up.
• Debris in the Inducer Assembly: Debris can block your fan wheel and keep it from turning. 
• Cracked or Damaged Wheel: Moisture accumulation, debris buildup, and wear can cause the wheel to become damaged or cracked.
• Electrical Failure or Capacitor Issues: Faulty capacitors, loose wiring, and other electrical problems can keep the motor from receiving enough power to operate.
• Pressure Switch or Vent Blockage Creating Similar Symptoms: If the pressure switch is malfunctioning or a vent is blocked, your furnace may shut off as a safety measure.

Safe Troubleshooting Steps for Homeowners

While some furnace inducer motor troubleshooting should be left to the experts, there are a few tasks you can safely handle on your own.

• Check Thermostat Settings: Sometimes, a furnace won’t turn on because a family member switched the thermostat’s mode or setting. Confirm your settings before you call for furnace repairs.
• Confirm Power at the Breaker and the Furnace Switch: Next, see if the breaker panel has tripped. If it has, you can try resetting it once. However, don’t continue to reset it if it trips again because this indicates an underlying problem that should be addressed by a professional. You should also verify that the furnace service switch is on.
• Replace a Dirty Air Filter: Air filters should be changed every 30 to 90 days. A dirty air filter can cause your furnace to overheat and shut off.
• Listen for Startup Sequence Clues: How your furnace sounds can help you determine the underlying problem. 
• Check for Obvious Vent Termination Blockage Outside: Verify that the outside vent termination isn’t blocked by leaves, a bird’s nest, snow, or debris.

Problems That Can Be Mistaken for an Inducer Motor Failure

There are a few common problems that might be mistaken for an inducer motor failure.

• Pressure Switch Problems: When the pressure switch is faulty, the switch may think that the inducer motor isn’t working when it is.
• Igniter Failure: If the igniter has failed, safety mechanisms will keep your furnace from running. 
• Control Board Issues: The control board must send power to the motor so that it switches on. Any malfunction in the control board can keep your motor from running.
• Blocked Flue or Intake Pipe: Blocked flues and intake pipes can keep your motor from pulling the air it needs to run.

How a Professional Diagnoses the Issue

When our HVAC technicians come to your home, we’ll quickly work to diagnose the cause of your furnace issues.

• Testing Inducer Motor Voltage and Amp Draw: First, we’ll use a multimeter to make sure your inducer motor is receiving proper voltage and drawing the correct current.
• Inspecting the Venting Path and Pressure Switch: Then, we will inspect the venting path for any blockages. Our technician will also make sure that the pressure switch is working properly.
• Verifying Whether the Motor Starts, but Cannot Maintain Speed: Our technicians will perform a test run to see if the motor is starting. If it can’t maintain speed, it may be due to a capacitor issue, worn bearings, debris in the flue or intake, or debris buildup in the fan wheel.
• Determining Whether Repair or Replacement Is the Better Fix: Once we know what the problem is, we can help you determine if repairing or replacing the unit is the best choice.

Common Fixes for Inducer Motor Problems

Depending on the underlying cause, there are a few methods we can use to fix your inducer motor-related problems.

• Clearing Vent Obstructions: By clearing the flue or intake pipe, we can make sure your unit gets enough airflow.
• Replacing the Inducer Motor Assembly: If your inducer motor is the main issue, we can replace the motor assembly.
• Repairing Wiring or Control Problems: For electrical problems and control board issues, we may need to replace the wiring or control board.
• Replacing Related Safety Controls When Necessary: Sometimes, the safety controls shut off a furnace incorrectly. In these instances, we can replace the safety controls involved.

When To Call for Furnace Repair

If you’re experiencing any of the following symptoms, it’s time to call in the professionals.

• Repeated Furnace Lockouts: When your furnace doesn’t detect a flame, it will shut off as a safety mechanism. This is a safety concern for your family, so call for repairs if you experience frequent furnace lockouts.
• Loud Noises at Startup: Any loud noises when your furnace starts up are cause for concern.
• No Heat During Cold Weather: When temperatures drop, you can’t afford to go without heat. To ensure your family’s safety and comfort, Rogue Valley offers 24/7 emergency services.
• Signs of Exhaust or Venting Issues: Combustion byproducts are hazardous to your health. If there are any signs of exhaust or venting issues, immediately shut off your gas lines and power to your furnace. Then, call for help.

How To Prevent Future Inducer Motor Issues

To avoid future problems with your inducer motor, remember to use the following maintenance tips.

• Annual Heating Maintenance: Scheduling annual heating maintenance can help you catch problems before they escalate into costly repairs and unexpected breakdowns.
• Vent Inspection and Cleaning: Periodically, inspect your vents for blockages and clean them. Besides reducing the wear on your inducer motor, this is also an important safety precaution.
• Early Attention To Unusual Furnace Noises: By paying attention to noises and performing furnace inducer motor troubleshooting early, you can avoid costly, complicated repairs in the future. Furnaces rarely break down without some type of prior warning, so immediately reach out for professional repairs as soon as you notice any signs of a problem.

FAQs

Can a furnace run with a bad inducer motor?

No, most likely not. The inducer motor is necessary for venting exhaust gases. If it isn’t working, the furnace’s control board will shut the unit down as a safety feature.

Is an inducer motor the same as a blower motor?

No, they aren’t. Inducer motors pull combustion gases out of the heat exchanger to protect your home and family. Blower motors are designed to push air through your ductwork.

How much does an inducer motor replacement usually cost?

The actual motor typically costs between $400 and $1,100. In addition to materials, homeowners will have to cover labor costs as well.