Is your whole house fan turning itself on or off? You might need to lubricate the bearing more often. Here are 6 fixes to try.

Let me paint you a picture. It’s a hot day outside, you’re fresh and safe in the comfort of your own home, relaxing on your day off. All is going well, and suddenly, the temperature starts rising at a concerning rate.

You wait for a couple of minutes, hoping that the problem will resolve on its own, but it just keeps getting worse. After some more time passes, you just can’t take it, and go up to the attic to see what’s going on.

Surprise, surprise, your whole house fan turned itself off.

How is this possible if you had left it on, knowing that it would be an extremely hot day? Well, there is no single answer to that question, but there sure are several possible explanations.

This could be happening as the result of an overheating motor, loose wiring, or even an insufficiently lubricated fan bearing. When you start thinking about it, the potential culprits just keep coming.

In order to successfully deal with them, and get your house fresh and cool once again, you need to know exactly what to be on the lookout for.

This is why I’ve created the list below, where you’ll find the most common causes to this unfortunate situation, and the simplest things you can do to address them.

Are you ready? Let’s get busy!

Fixing a Malfunctioning Whole House Fan

The idea of repairing your own whole house fan can be intimidating. Especially if the installation was done by a technician, but you’d be surprised at how simple many of the possible solutions to this problem can be.

In numerous cases, making sure that your fan bearing is properly oiled, and inspecting the blades for damage from time to time, should be more than enough to keep it running smoothly.

Here are the 6 fixes you can try to repair your whole house fan:

  1. Check the motor
  2. Inspect the blades
  3. Lubricate the bearing
  4. Look for loose wires
  5. Test your thermostat
  6. Replace your capacitor

#1 Check the Motor

The first thing I want us to take a look at, is your motor.

This part can fail for a number of reasons, but the most common ones are overheating, short-circuiting, a lack of oil, and factory defects.

Provided that you’ve owned your whole house fan for a very long time, we can safely rule out the latter. Overheating and short-circuiting can happen as a result of improper operation or large power surges, while malfunction due to insufficient oil, can arise from user-derived neglect.

Whatever the case may be, it is of the utmost importance that you address this situation as soon as possible, as a malfunctioning motor could not only be causing your whole house fan to keep turning itself on or off, but also do permanent damage to the unit.

Solution: Give your whole house fan proper maintenance and make sure to top it up with oil every couple of years. Provided that you’re still in time to implement preventive measures, this should fix the problem.

#2 Inspect the Blades

steel fan blades
Minor damage to your blades could create a lot of trouble in the fan’s motor

This might surprise you, but even the slightest damage to your fan blades can affect your appliance’s ability to function properly.

As you can imagine, your whole house fan is designed to operate under very specific conditions, such as a certain amount of air flow, temperature, and electricity. When any of these factors is compromised, you could be stuck with a unit that keeps turning itself on it or off.

Damaged fan blades could create excessive resistance when sucking in air, causing the machine’s motor to overheat.

Solution: Carefully go up to the attic and gain comfortable access to your fan’s blades.

The process to do this will vary from model to model, but the broad strokes should be fairly similar for all of them:

  1. Switch off the breakers supplying electricity to the fan
  1. Locate the screws holding the outer panel vent in place, and undo them with a screwdriver
  1. Remove the vent panel
  1. Gain comfortable access to the fan
  1. Look for bending or damage in the blades
  1. Replace them if you find any

#3 Lubricate the Bearing

If this is the reason why your whole house fan keeps turning itself on or off, you’re lucky, as adding some motor oil to the bearing should do the trick.

Just as it happens with any moving part inside household appliances, a bearing needs lubrication to rotate with the minimum amount of friction. Modern motor oil is designed to last for a very long time, but it’s not eternal.

If you’ve owned your whole house fan for a couple of years now, and you’ve never changed the oil in the bearing, this problem could be your machine’s way of telling you it desperately needs to be topped up.

Failing to adequately keep your whole house fan lubricated could lead to overheating, and eventual general malfunction.

Solution: Keep a container full of motor oil handy at all times. You can use it to properly maintain both your machine, and other appliances that might need it.

#4 Search for Loose Wires

exposed electric wires
Electrical wires in your house could break or come loose over time

This might be a bit of a stretch, but hey, we want to cover all bases, right?

Whether it was you or a certified professional who installed your whole house fan, the chances of having made a mistake when setting up the wiring are very low, but never zero.

And even when the installation was done correctly, some wires could have broken or come loose over time, as the appliance operated. If this is the case, it would explain why your machine keeps turning itself on or off, as intermittent activation could occur when loose wires come in contact with each other.

If you suspect this to be the culprit, please stop using your appliance immediately.

Solution: The process to check for loose or broken wiring is quite similar to that of checking the blades, but there are some slight differences:

  1. Switch off the breakers supplying electricity to the fan
  1. Locate the screws holding the outer panel vent in place, and undo them with a screwdriver
  1. Remove the vent panel
  1. Remove the fan
  1. Gain comfortable access to the unit’s wiring, and look for anything suspicious

While a broken cable should be very easy to identify, having your appliance’s wiring diagram handy could make your life a lot easier.

#5 Test Your Thermostat

A temperature-regulating machine with a faulty temperature-regulating component is a modern day nightmare.

As you probably know, every whole house fan is equipped with a thermostat that is in charge of both sensing the temperature inside the unit, and regulating it accordingly to prevent overheating, and other potentially dangerous events.

When this part fails, your appliance becomes incapable of accurately sensing what is going on inside it, which could trigger an automatic deactivation, even when it’s not hot enough to pose any danger to its other internal components.

If this is the reason behind your machine’s malfunctioning, the news are not all bad. On one hand, you do have a broken thermostat, but on the other, everything else inside your whole house fan should be working fine.

Solution: Please follow the steps from the previous point to expose your appliance’s internal components and wiring. If you have a multimeter, you can use it to test the part for continuity.

#6 Replace the Capacitor

leaking capacitors
The fan’s motor can not work without a working capacitor

Lastly, let’s take a look at your capacitor.

This is the lifeblood of your appliance. Without it, your motor cannot function.

It’s that simple.

Diagnosing a malfunctioning capacitor can be tricky, as, depending on the damage to it, your whole house fan might not even turn on, but if it’s only partial, it could be allowing for intermittent operating cycles, resulting in a unit that keeps turning itself on or off.

Just as it happens with nearly every other item on the list above, as soon as you suspect this to be the culprit, you should stop using your appliance immediately.

Failing to do so could turn minor or partial damage, into a total loss.

Solution: Please follow these steps from point #4 to gain access to your appliance ‘s internal components. Once you have done that, carefully unscrew the motor and place it somewhere where you can work on it comfortably.

The capacitor should not be too hard to identify or replace, but if you want a detailed walkthrough that you can follow along step by step, there are tons of online videos you can check out.

Conclusion

To have your whole house fan keep turning itself on or off can be very inconvenient. Especially if it starts happening during hot months.

Luckily, as I hope you’ve learned on this piece, addressing most of the issues behind this occurrence is not too difficult, and should not take up a lot of your time.

More often than not, making sure to give the appliance proper maintenance is all that is needed to keep it working normally, and last for a very long time.

Thank you for reading. If you found this article helpful, why not become an expert in the topic by checking out our other wonderful resources below?

Stay cool!