How To Check The Furnace Blower Motor? Essential Guide


Rima Chatterjee

Checking Blower Motor Of Furnace: An Overview


Frustrating, isn’t it, when your HVAC furnace blower motor isn’t working? Here’s my advice on what to do. The blower motor pushes air through ducts and vents. If it’s not working, you’ll get weak airflow or cold air coming out of the vents. Don’t wait, or it could lead to overheating or expensive repairs.

How To Check The Furnace Blower Motor

Gather your tools: a multimeter, wire probes, and a battery. Turn off the power supply and remove the access panel. Check the wheel and housing for wear or damage. Also, look for worn-out belts or capacitors.

  • Identify the blower motor terminals. 
  • Use the multimeter to test for proper voltage and resistance readings. 
  • There should be a sequence of voltage readings for each speed wire. 
  • Out-of-range readings could mean a bad blower motor or control board.

Test for continuity between all wires. And don’t forget to check the windings’ resistance with the multimeter battery.

Take action right away if you suspect a problem. Delays can cause further damage and more costly repairs.

Signs of a Bad Furnace Blower Motor


To identify signs of a bad furnace blower motor, you need to conduct a comprehensive inspection of the system. I will introduce you to  Each of these sub-sections provides crucial insights into the possible causes and solutions to common symptoms: weak airflow, overheating, short circuit, burnt-out motor, and a bad capacitor. ions to the problem. So, let’s explore each case in detail to take the necessary action for repair and restore proper HVAC system operation.

Weak Airflow of Furnace

Do you feel weak airflow coming from your furnace? It could be a sign of a bad blower motor. This means warm air isn’t being spread around your house, which can cause discomfort and harm your heating system. If you leave it, the motor might fail totally.

To find the problem, first, look at the air filter for blockages or buildup. If none, the fan belt may be loose or worn. For more in-depth checks, call an expert.

To keep the blower motor in good shape, book regular maintenance and cleaning with a qualified HVAC professional. This will help catch any issues early and make your heating system last longer.

If your blower motor is heating up too much, you need to quickly find a new one before your home feels like a sauna!

Overheating of Furnace

When a furnace blower motor overheats, this can cause potential hazards and reduce the unit’s efficiency. It might be due to a malfunctioning fan or dirty air filters. Vibrations from worn-out belts or bearings can also heat up the motor.

Maybe your furnace is running constantly or takes too long to warm up your home. Unusual noises and smells can indicate a problem with the blower motor.

To stop further damage, contact an HVAC technician to inspect and fix the furnace’s blower motor. Regular maintenance can prolong the unit’s lifespan and keep it running optimally.

Change air filters often and keep the area around your furnace clear. That way, you can avoid an overheating issue.

Short Circuit in Furnace

Maintaining proper electrical connections is key for furnace blower motors. If there’s a short circuit, it can cause major damage to your HVAC system. This happens when an electrical current follows an unexpected path because of a broken wire or loose connection. It can create heat and spark, which can damage the motor and other parts of the furnace.

If you detect smoke or a burning smell from your furnace, that’s a sign of a short circuit in the blower motor. Watch out for frequent tripping of circuit breakers or fuses, odd noises from the furnace, and irregular thermostat functioning too. Ignoring these symptoms can lead to costly repairs.

Maintenance and timely repair will prevent such catastrophes. If you’ve been using your furnace for over five years without any maintenance, the chances of a short circuit in the blower motor are high. Get a professional technician if you hear strange sounds or smells from your HVAC system.

In 2005, 47,000 fires in residential buildings in the US were caused by heating systems. Property loss from this added up to over $425 million (National Fire Protection Association). Short circuits were a major cause of these fires

So, it’s important to pay attention to signs related to your furnace blower motor to help avoid disasters like this.

Burnt Out Motor of Furnace

A furnace blower motor is key for the circulation of hot air in your home. But when it’s burnt out, your house can become cold and uncomfortable. Signs of a bad motor?

  1. Strange noises
  2. High energy bills
  3. Reduced airflow
  4. Not starting

If these signs are there, get an expert in fast!

It’s vital to fix a worn-out motor – it can be dangerous. Overheating, fire, and carbon monoxide poisoning can occur from inadequate ventilation. Carbon Monoxide is a deadly gas that can cause fatigue, headaches, and even death. Don’t risk your safety!

Remember: regular maintenance of your appliance helps it last longer and work better. If you need info on how to spot a faulty blower motor or help with repair/maintenance, HVAC Technician Los Angeles can help. 

Like a rock band, a bad furnace blower motor needs a drummer to keep the beat steady – a bad capacitor!

Bad Capacitor of Furnace

A faulty furnace capacitor can be a cause of blower motor problems. It can make the motor run slower or not start. Signs of a bad capacitor include humming, burning smells and the air conditioner not working.

The capacitor helps start the blower motor. If it fails, it could overheat the system and damage other parts. Get a technician to replace a bad capacitor quickly.

It’s really annoying when your HVAC system won’t turn on due to a broken capacitor. Be prepared and have your furnace checked regularly by experts to avoid expensive emergency repairs. Schedule maintenance checks with an HVAC expert to keep all components running well.

Checking a blower motor is like doing surgery on your heating system – without the medical degree!

Steps to Check a Furnace Blower Motor


To check your furnace blower motor with the steps outlined in this blog post, start by turning off the power and removing the access panel. Then, you’ll need to locate the blower motor. From there, you can check the motor terminals for proper voltage and test the blower motor operation. To get a comprehensive overview of your blower motor’s health, you’ll want to measure its amp and resistance readings. Finally, inspect the blower wheel and housing for any damage that could be causing weak airflow or overheating in your HVAC system.

Turn off the Power and Remove the Access Panel of the Furnace

When dealing with the furnace blower motor, safety is key. Put on gloves and protective gear as a precaution. Here are 6 steps to follow:

  1. Find the circuit breaker box and switch off the power.
  2. Unscrew or unlatch the access panel.
  3. Lift the panel and place it aside.
  4. Take a flashlight and look out for any visible signs of damage or dust.
  5. Check if there is debris around the fan motor.
  6. Secure the access panel when done.

Cleaning air filters and ducts is important too. This way, you can ensure your furnace motor works for years, without risking any harm to yourself. 

Ready? Find the hidden furnace blower motor!

Locate the Blower Motor of the Furnace

To find the furnace blower motor, follow these six steps!

  1. Turn off the power to the furnace.
  2. Remove the front panel by unscrewing its fasteners.
  3. Search for the blower assembly; it should have a wheel and housing attached.
  4. Look for a label that identifies the unit as the blower motor or consult a manual.
  5. Check for any visible damage or debris using your flashlight.
  6. Put on proper safety gear and test if the motor spins by rotating its central shaft.

Also, be alert for any unusual noises coming from the unit when testing. To keep your HVAC system running optimally, remember to implement routine maintenance schedules. 

Don’t wait for subpar heating, do regular inspections and make repairs promptly! Use a voltmeter, not your tongue, to check motor terminals for voltage.

Check the Motor Terminals of the Furnace for Proper Voltage 

Having trouble with your furnace blower motor? Voltage might be the issue! Here’s how to check.

  1. Turn off the power to the furnace. 
  2. Uncover the motor using a screwdriver and make a note of the wires.
  3. Grab a multimeter and, on the ohm setting, place one probe on each terminal. Turn on the power and check the display.
  4. Check the reading against what should be expected from the furnace’s documentation or manufacturer’s website. 
  5. If it’s below or above, further inspection or replacement is needed.

Remember, electric components can be dangerous so only do these steps if you have experience, and always prioritize safety. 

Don’t let a faulty blower motor spoil your winter – check it now! Stay nice and toasty this season!

Test Blower Motor Operation of Furnace

The correct functioning of a furnace’s blower motor is essential. Regular checks are necessary to ensure both comfort and safety. Follow these four simple steps to check it:

  1. Turn off the furnace – Allow it to cool down.
  2. Locate the blower motor – Look around and near the furnace housing.
  3. Inspect the belt – It should be connected to the fan blade attached to the motor shaft. Tighten or replace if it is loose or worn out.
  4. Test the motor operation – Turn on your furnace and listen for a running sound and check for air movement. If you don’t, call for professional assistance.

Maintenance is important to prolong durability and enhance furnace efficiency for a better home heating experience.

The first hot air furnaces were invented by the Romans over 2000 years ago and were called hypocausts – they were made from brick or stone-enclosed fires.

Time to get technical! Measure those amps and resistance – no need for engineering knowledge, just tinker with wires and circuits.

Measure Amp and Resistance Readings of Blow Motor

  1. Turn off the power supply to the furnace and remove the motor cover.
  2. Use a digital multimeter to measure both ampere and resistance.
  3. Create a table with two columns – one for ampere readings and another for resistance readings.
  4. In the ampere column, note down the actual data reading.
  5. In the resistance column, write down the exact value of the electric resistance observed.
  6. Different motor types may require specific measurements or ranges of values.
  7. Ensure accurate readings to troubleshoot underlying issues.
  8. If readings are fluctuating wildly, check for rust formation – a possible cause.
  9. If rust is present, replace the entire blower coil and clean up all rust deposits.
  10. Looks like the blower wheel needs a hug from a repairman!

Inspect the Blower Wheel and Housing for Damage to the Furnace Blower Motor

Examining the blower wheel and housing for harm is a must when checking the furnace blower motor. 

Inspect the wheel for rust or cracks and replace it if you find any. These can cause vibrations and issues in the long run. Also, make sure the housing is clear of dirt or debris that might limit the airflow. 

Also, check for bent blades or cracks in the housing if you hear weird noises.

Remember to include this in your regular maintenance! Alice Parker, an African American female inventor, invented the first furnace in 1919.

Using a multimeter to check the blower motor is a necessity. We must pay attention to the voltage here.

Using a Multimeter to Check a Blower Motor


To check your furnace blower motor, I’ll share with you my method using a multimeter. With this solution, you will be able to diagnose problems with your blower motor like overheating or weak airflow. First, we will cover the basics of DC voltage and continuity before moving on to test for voltage and continuity separately. These steps will enable you to determine the source of the problem and take action to repair the issue.

Understanding DC Voltage and Continuity

DC voltage is a current that only flows in one direction. AC voltage, however, alternates its flow. To understand DC voltage, use a multimeter to measure the levels. Continuity ensures electricity is flowing well. Check this by setting your multimeter to “continuity test” and touching its leads to either end of the wire. If there’s no resistance, you have continuity.

Safety comes first when doing electrical repairs. Electric shocks can be fatal and dangerous, so wear protective gear. Thermography cameras and multimeters make diagnosis easier. They can locate hotspots in an electrical system and prevent possible failures.

Let’s crank up the voltage and find out if this blower motor is a hit or a miss.

Testing for Voltage

Voltage testing is necessary to check a blower motor’s performance. Make sure the motor has power and use a multimeter to measure voltage. Use the following steps for checking:

  1. Find the blower motor connector.
  2. Set the multimeter to DC Voltage.
  3. Plug the red test lead into the “VΩmA” port on the multimeter.
  4. Plug the black test lead into the multimeter’s “COM” port.
  5. Turn on the vehicle’s ignition switch so that the battery has a power supply.
  6. Connect the red prong of the ohmmeter to the positive terminal of the blower motor, and the black prong to the negative terminal.
  7. Check the voltage readings, there should be power between the terminals. If there’s no voltage reading, replace the blower motor relay or resistor.

Remember to wear protective gear when conducting electrical tests. Also, look out for damaged wires or physically broken components needing replacement.

Once the correct voltages are found, double-check your measurements after connecting everything back up. Make sure the multimeter’s test leads are tightly connected to the ports and motor terminals for accurate readings.

Time to get your beep on! Testing for continuity just got electrifying!

Testing for Continuity of Furnace Blow Motor

To assess the blower motor’s function, check for continuity. This means seeing if electricity can pass through a circuit. 

  • To begin, detach the negative battery cable
  • Disconnect the blower motor’s electrical connector and figure out which pins control the ground & power wires. 
  • Then, set the multimeter to “Ohms”. 
  • Probe each wire and measure resistance levels between 0-20 Ohms
  • If results are outside of this range, you may need to replace the blower motor.

Before checking continuity, investigate other potential causes. This may include fuses, relays, or other electrical issues. 

Keep your furnace blower motor happy with maintenance as nobody wants a grumpy HVAC system!

Maintaining Your Furnace Blower Motor


To maintain your furnace blower motor properly and ensure its smooth operation, the solutions to consider are changing air filters regularly, lubricating moving parts, and checking fan belt tension. These sub-sections are important to keep your furnace blower motor working effectively and prevent any potential damage or problems. By following these simple steps, you can increase the lifespan of your motor and save yourself from time-consuming and costly repairs down the road.

Changing the Air Filters of the Furnace Regularly

Keeping up with regular air filter changes is a must for your furnace blower motor. Overlooking it can cause a lot of problems, from bad air in your home to costly repairs. Here are 4 tips:

  1. Get the correct filter: Search for a filter with a high MERV rating. This makes sure more particles are gone before they get to your blower motor.
  2. Change filters every 1-3 months: Filters clog up quickly, particularly if you have pets or allergies. Put it down on your calendar so you don’t forget!
  3. Watch out for warning signs: If you see weak airflow or strange smells from your vents, it’s time to switch the filter.
  4. Hire a pro if needed: Some furnace systems need more technical expertise than others. If you’re uncertain about how to change the filter or think something may be wrong with your system, it’s better to call in an expert.

Did you know that changing filters wasn’t always common? Earlier, furnaces were usually put in neglected places like basements or attics. It was only when the energy crisis of the 1970s happened that people began to notice energy efficiency and proper furnace care became more common. Now, changing filters often is seen as a key part of keeping your furnace and home running well.

Remember: a lubricated furnace blower motor is like a good marriage – it runs smoothly and with minimal friction.

Lubricating Moving Parts

It’s essential to keep your furnace blower motor in tip-top shape. Lubricating the moving parts is one way to ensure your motor runs smoothly and efficiently. Not doing so may require costly repairs or a full replacement. Here’s a 5-step guide for lubricating your furnace:

  1. Turn off the power: Locate the circuit breaker powering your furnace and switch it off.
  2. Identify lubrication points: Refer to the manufacturer’s manual or get help from a professional.
  3. Clean the parts: Use a cloth or soft-bristle brush to remove dirt, debris, and old lubricant.
  4. Apply lubricant: Put the right amount of lubricant as indicated in the manual. Avoid over-lubrication or under-lubrication.
  5. Testing: Turn the power back on and run your furnace for a few minutes.

Know when it’s time to service your furnace. Generally, you should do it every 1-3 years, depending on usage. 

Energystar.gov says that lack of maintenance can cause up to a 50% failure rate

Don’t forget to check the fan belt tension too!

Checking the Fan Belt Tension of the Furnace Blower Motor

Maintaining the Furnace Blower Motor is essential for optimal furnace performance. Checking Fan Belt Tension is a key part of regular maintenance. The tension must be neither too tight nor too loose. Checking it often prolongs the motor’s life and prevents potential damage.

Here’s how to check tension:

  1. Turn off the power. Find the switch and turn it off.
  2. Remove any panels or covers blocking the blower assembly.
  3. With a ruler, press down on one of the pulleys with 10 lbs of force. If there’s 0.5-1 inch of slack, it’s at the right tension.
  4. Adjust the bolt or adjusting rod with a wrench until it’s at the right tension.
  5. Reassemble everything and test-run the machine.

Check for cracks and frays on the V-belts too. If they show wear, replace them. Have a certified professional do this as tampering with electrical components can be dangerous.

Good maintenance of your furnace blower saves energy and prevents breakdowns in winter. Spend some time every month inspecting the system components and doing proper maintenance. This will save electric bills over its lifespan.

Take control of your household climate! Make these small changes so you can always have savings! Keep your furnace blower motor happy and it’ll provide hot air all winter.

Conclusion


Checking a furnace blower motor is essential for proper HVAC system operation. My blog post covers using a multimeter to test motor winding resistance, checking motor speed, and examining the blower wheel and squirrel cage for damage or wear. Homeowners can identify a failing blower motor before it causes further issues. Potential symptoms of a bad blower motor are weak airflow and overheating. Homeowners need to take action at the first sign of trouble, replacing parts such as capacitors and filters. Safety precautions should be taken when handling electrical components. The power supply to the unit should be disconnected before beginning work and wear security service gloves if comfortable with electricity. If you can’t identify the problem, consider calling in professional HVAC repair services. 

About the author

Debarghya Roy: A heating systems author, Passionate about energy efficiency and sustainability, Sharing insights and empowering readers through informative blog articles.