How To Lubricate Furnace Blower Motor (How Often, Lubricant)

When it comes to furnace blower motors, you have to determine what type it is. It could be the traditional belt-driven model, or it could be the direct drive option. The latter does not need lubrication but the former model does.

Some RV owners use sewing machine oil to lubricate their blower motor, others use different oil brands and types. However, when your blower moor starts squealing, lubrication is only a temporary fix. Replacement is the ideal repair.

To learn more about this topic, just continue to read our article. It explores the topic so you have the best information possible. Once the squealing starts it may never end until you break down and buy a new motor.

How do I Stop My Furnace Blower Motor From Squeaking?


The first thing you need to know is that lubrication is only going to provide temporary relief. Eventually, the lubrication will wear off and you will have to deal with the same problem all over again.

Lubrication is good if you are miles away from a town or city that has a company that sells replacement blower motors. The second thing to know is that different furnace brands may allow access to the motor while others may not. That is without having to pull the whole furnace out.

Some RV owners recommend a light viscosity oil, like sewing machine oil, and they say you only need a few drops to lubricate the bushings. You may have to apply a few drops as the motor is running so the oil wicks in and gets to the unlubricated area.

There are different lubricants you can use but motor oil is not one of them. One furnace expert stated that motor oil will short out the windings leaving you with a bigger problem.

There are some good alternative lubricants you can use that will help reduce or remove the noise once it hits those bushings. There are differing opinions on which type of oil you should use.

Can You Lubricate a Blower Motor?

Yes, you can, and even if you do not have direct access to the motor, a long spout can help you reach the motor and let you put the oil where it belongs. How much work and access you have will depend on the furnace brand as well as the brand of your RV or trailer.

In many cases, the advice you will get from your fellow RVers is that lubricating is a waste of time as it is only a temporary fix. They will recommend that you replace the motor and that will solve the problem for at least another 25 years.

Of course, replacement may not be an option at the moment for many RVers as their budget won’t allow it or they are stuck far from civilization and won’t be back for a few days. In those situations, then lubrication is your only option.

Just be prepared to hear the noise once the lubrication has worn out. If you are one of the lucky ones and have to pull the furnace to reach the motor, this is never good news. Check into the replacement option to see if this is the better route to take.

How To Lubricate Furnace Blower Motor


The first step in this process will be to determine if your furnace blower motor is dying or if it just needs lubrication. If it is dying, then the only fix is a replacement motor. If it just needs lubricating, you have several duties to perform.

A lot of the time, the noises you hear come from the fan and not the motor. So the second step would be to clean out the fan area, including any nests small animals have built in the fan cage. If this stops the noise, then you are done.

If not, make sure to lubricate the motor and the fan through the oil ports the manufacturer placed on their furnaces. Sometimes you can place the oil on the shaft and then turn the motor by hand till the oil wicks in.

While you are working on the fan and the blower motor, check to see if the fan loosened up at all. If it did, then that may be the source of the noise you hear and you won’t need any oil. Just tighten the fan and the noise should stop.

Keep in mind that if the lubricating did stop the noise, start budgeting to buy a new blower motor. It is on its last legs and will need replacing sometime soon in the future.

Lubricating Squirrel Cage Fan

To start, the best tip that can be given is for you to NOT use any lubricant that is flammable. You do not want to add to the risk of fire in your RV, etc. Instead, check your owner’s manual to see if it provides a brand name for the type of lubricant you should use.

Most people recommend sewing machine or similar viscosity oils. Others will recommend the lubricants you will find at this Amazon link. Read the reviews to get an idea of which one will be best for you to use.

Next, you should remove the squirrel cage from the furnace so you have better access to all the parts. Once the cage is out, look for the oil ports most manufacturers place on their devices.

You will not need a lot of oil here, but make sure to add only a few drops to the oil ports. If you do not find any, then try to oil the shaft or other areas close to the bushings. After the oil is in place manually turn the squirrel cage so the oil can penetrate.

The recommended amount of oil you should use on a squirrel cage is between 3 and 5 drops. This is sort of like lubricating a sewing machine. A little does a lot and less is more.

How Often To Oil The Furnace Blower Motor?


This information may be in the service or the owner’s manuals. Each manufacturer has their own recommendation on this topic and you should get the instructions from them.

However, you will only need a few drops after so many hours of operation have passed. The exact time frame should be listed in the manuals. If not, call the dealer or the company to get this information. It is not going to be the same for every brand or model.

If your RV has the direct drive operation in its furnace, you may never have to lubricate. It is a closed system. When it comes to the squirrel cage, it is recommended that you lubricate once a year.

Again, it cannot be stressed enough, that if your blower motor or fan is making noise, replacement is the only option to stop the noise. Lubrication is only a temporary fix.

When you go to buy a new blower or fan, replace the entire unit to make sure you solve the problem. Doing this repair piece meal will not work for you and leave you with the problem unsolved.

Make the best decision for your camping or RV situation. You can only delay replacement not avoid it.

Can You Spray WD40 on a Furnace Blower Motor?

If WD 40 is oil-based, then it is not a good idea to spray it on electrical units. Once on the windings, WD 40 can weaken them and then, in turn, damage the motor.

This product is not a real lubricant but a penetrating oil. That means that if you spray this product on your fan or blower motor, you will not get much lubrication and you may not rid yourself of the noise.

What you want to use instead will be a lubricant that is made for high-speed situations and motors. That way you can get the lubrication you need and it should last longer than what WD 40 can do.

If you want, you can use a 3 in 1 oil instead of sewing machine oil. It works just as well. But the advice to not use WD 40 is unanimous. This product is just not made for this type of application.

It would work if the fan was stuck and could not spin. WD 40 would help loosen the fan and make it spin again. After that, you would have to add some lubricating oil to the oil ports to make sure the fan keeps spinning.

It is tempting to use WD 40 for most applications as it does many things for you. This is just one of those times it can’t help.

What is The Best Lubricant For a Furnace Blower?


The following list is not given in any particular order. All the brands listed should be good to use. The key is to not use WD 40 even though it is often advertised as a lubricant.

1. Sewing machine oil- We have mentioned this product many times already. Singer and other sewing machine companies make top-quality oils for their machines. They will work for your blower motor. The oil is on sale where sewing machine products are sold.

2. 3 in 1 oil- A great lubricant as it is specially formulated to meet high-speed applications. The oil is easy to use and comes in a squeeze bottle format. This design helps cut the splatter and overspray problems you find with other oil formats.

The product has been around for 40 years and has built a solid reputation over that time. It works well.

3. Trick shot lubricating penetrating oil- This is an eco-friendly lubricant that can be used on blower motors as well as other motors. The ingredients help remove rust, and hinder corrosion, as well as a cleaner.

It works well and has many applications. The lubrication aspect makes sure to cut down on friction.

4. CRC 2-26 Multi-Purpose Precision Lubricant - This is a spray can version but that should not hinder its application or its performance. Simply spray on the affected areas of your motor and let it do its work.

The lubricant has been around since 1958 and it is made from specialized ingredients to provide fast-acting lubrication when you need it most.

5. Max Professional 4125 Electronics Lubricant- This product should clean as it lubricates helping to reduce the source of your noise problem and keep it away a lot longer than other lubricants.

The drawback to this product is that it can be very expensive.

The Drip Caps

When your blower motor is starting to make noise and you want to quiet it down. One of the things you have to look for first is the oil ports. There should be one on each side of the motor so it gets lubricated evenly.

To find these oil ports, look for the plastic drip caps. These caps keep the dirt and dust from entering the motor through those oil ports and help the motor last longer.

Once you remove these caps put them in a safe place as you do not want to use your furnace without having them in place. Keeping your blower motor clean helps it remain working without noise for a very long time.

As a reminder, you should only use about 3 to 5 drops of oil every time you lubricate the blower motor. The manual should tell you how many drops you actually need when it comes time to lubricate the motor.

Some Additional Words

When the blower motor starts making noise, you know it is time to think about replacing it. The noise is telling you that the motor is on its way out and a new one is required.

It is okay to lubricate the motor but this will only delay the inevitable not solve the problem. When you talk to other RV owners, do not be surprised to hear several different opinions on what is wrong, what you should do, and which lubricating oil to use.

Leave a Comment: