How to Lubricate Furnace Blower Motor: A Step-by-Step Guide

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Are you having trouble with your furnace blower motor? If so, you’ve come to the right place. In this blog post, lubricationfaqs will be discussing a step-by-step guide on how to lubricate furnace blower motor. By following these simple instructions, you can ensure that your blower motor runs smoothly and efficiently, helping to keep your home warm and comfortable. So, let’s dive in and learn how to lubricate your furnace blower motor like a pro!

About Blower Motor

Depending on how old and how the furnace was built, there are differences in the shape and placement of HVAC circulating fans and blower motors. The majority of the time, however, it is a cylindrical fan with an associated motor that is situated in the furnace’s bottom compartment beneath the combustion chamber. Because it resembles the little exercise wheel used in cages for squirrels, mice, and other pets, this fan design is frequently referred to as a “squirrel cage”.

This blower moves air through the evaporator coil or heat exchanger of the air conditioner, the ventilation ducts, and air registers in the rooms as it moves upward from the system return duct.

Older furnaces may include a motor positioned on the side of the blower that powers the squirrel cage blower. This motor turns the fan by way of a belt that transfers rotation from the motor’s axis of rotation to the fan’s axis of rotation. Since the motor and blower are distinct components in this type, one or both components may be repaired or replaced.

Modern furnaces frequently employ direct drive systems, in which the motor’s main shaft directly powers the blower wheel. These can integrate the motor and blower into a single integral unit, and there are no fan belts to adjust or replace. The motor component may be affixed to the end or housed inside the blower wheel. Normally, the blower motor is the only component of this type that can be removed and replaced, however in some designs, these components are integrated and can be done so as a single unit.

Signs You Need to Lubricate Your Blower Motor

In order to force air through the vents in both cool and warm weather, your blower motor operates. As a result, you should be aware of any odd noises. Rattling noises or obnoxious engine noises may be easily fixed in some circumstances, meaning HVAC service is not necessary. The time to call a professional is when you’ve tried everything and the noise persists. Common noises and their causes include, among others:

  • Noises from the fan that are rattling or rattling because of brackets or screws that are loose.
  • Engine noise brought on by rusted or underlubricated bearings.
  • Dirty fan or air filter is the cause of the fast cycle on and off.
  • It could be that the fan and motor are dusty, or that the blower motor needs to be restarted, for the reason that the fan cannot run at different speeds.
  • If the furnace loses electricity, the blower motor needs to be restarted, or the motor is burned out, the blower motor will not operate at all.
  • Fans and filthy motors are to blame for the vents’ reduced airflow.

How to Lubricate Furnace Blower Motor

How to Lubricate Furnace Blower Motor

Starting and Cleaning Furnace Blower Motor

Turning off the furnace’s power is the first step in getting to the blower motor. You should be able to view the motor itself if you remove the screws or clamps from the blower motor control panel. You will need to grease the shafts and bearings as well as other components of the engine. The blower motor must be carefully removed from the oven after the bolts holding it in place have been removed. Place the blower motor on the floor close to the oven and take care not to overtighten the provided cords.

There is a set screw on the side of the blower motor housing. Remove the bolts holding the motor to the housing by loosening the screw first. Remove the fan motor from the housing with care. To clean the fan and motor and get rid of any extra grease you see around the accessories, use a brush or a can of compressed air.

You may also like: Quick and Easy Guide: How to Lubricate a Window Air Conditioner

Lubricating Furnace Blower Motor

Most furnace fan motors come with a self-lubricating mechanism, but if yours doesn’t, you’ll need to manually lube it. Track down the engine’s oil ports. Here is where the oil needs to be rubbed in. Purchase a blower motor oil without detergents that is designed exclusively for the furnace. Use only one type of oil for this technique; multifunctional oil should not be used.

As part of your regular maintenance regimen, you may need to periodically oil the motor bearings on older furnaces because the blower motor may have oil ports on it. It only requires taking off the cap and adding a few drops of mild machine oil to the reservoir. Follow the manufacturer’s recommendations for how often to oil the engine and what kind of oil to use. Newer blower motors typically have totally sealed bearings and never require oiling.

If the blower wheel itself has lubrication ports, grease the blower wheel bearings by adding oil to the openings. Some more recent blowers are made to make it impossible and unnecessary to lubricate the impeller.

Every year, an oil port on an engine should be greased. 10 ounces of undiluted engine oil (not general purpose oil) should be applied two or three drops per port. Limit your lubrication. The same method should be followed each year to lube the blower shaft if it has an oil port.

Once the furnace blower motor has been properly lubricated, carefully and precisely repeat the previous removal processes to reinstall and insert the blower motor back into the oven. Once the engine has been properly lubricated, make sure to wipe up any extra grease. The blower motor can overheat if there is residual oil on any of its components.

Restart the blower motor once it has resumed to bring the furnace back online. Any strange noise should go away if the blower motor is the cause when the oven is run through a typical cycle. If they continue, it’s likely that the furnace’s other components are where the issue originated, in which case you should contact a qualified HVAC technician for diagnostic and repair.


In conclusion, properly lubricating your furnace blower motor is an essential maintenance task that can help improve the efficiency and longevity of your furnace. By following this step-by-step guide, you can ensure that your blower motor remains in optimal working condition. Remember to always refer to your manufacturer’s guidelines and use the recommended lubricant. Regularly lubricating your furnace blower motor will not only keep it running smoothly but also contribute to a more comfortable and energy-efficient home.

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