The Indications for Bathroom Exhaust Fan Motor Replacement

You might take your bathroom’s exhaust fan for granted, but it’s essential in mitigating the humidity in your bathroom to keep mold, mildew, and water damage at bay. The heart of the exhaust fan is the motor—when the motor fails, the entire appliance ceases to function. 

How can you know when your exhaust fan is approaching a breakdown? We’ll run through some of the most important signs. With a little forewarning, you can have time to decide whether a full bathroom exhaust fan replacement or quick one-off repair makes more sense for your home.

Why Is a Bathroom Exhaust Fan Important?

Most local codes require a bathroom exhaust fan installation when the bathroom is without a window, but even bathrooms with windows should really feature a fan. An open window simply does not provide the same benefits as an adequate exhaust fan. Here’s why an exhaust fan is so important:

• Moisture control. Bathrooms are subject to high humidity levels because of residential shower usage. All of that steam and airborne moisture must be channeled outside to limit the possibility of mold and mildew growth. Keeping the bathroom reasonably dry also prevents rust, staining and discoloration, warping, and other defects brought on by the damp.
• Ventilation. Bathrooms have a tendency to get stuffy. Humidity, bathroom odors, limited square footage, and lack of cross-ventilation can all contribute to stale air. An exhaust fan resolves that problem by facilitating airflow and supplying the bathroom with fresh air.
• Odor mitigation. Bathrooms have the unfortunate tendency to collect unpleasant smells. An exhaust fan can eliminate foul odors more quickly and efficiently than an open window can.
• Temperature management. The steady circulation of air can help maintain a more comfortable temperature in the bathroom. Whisking away that hot, humid air after a shower prevents the bathroom from feeling too warm. Some fans also have built-in climate features. A bathroom exhaust fan with heater capabilities, for example, can keep you from catching a chill when you step out of the shower or bath in the colder months.

How Does a Bathroom Exhaust Fan Motor Work?

Exhaust fans are reasonably simple appliances. A small electric motor powers a fan at one end of a ventilation duct. The spinning blades of the fan draw the air from the bathroom, into the duct, and then expel it through a vent, outside the home. 

Drawing air from the bathroom creates a pressure differential. You can think of it as air from elsewhere in the home moving in to fill the negative space. This action ensures that the air within the confined space of the bathroom doesn’t stay too humid, too stale, too musty, or too malodorous.

A ceiling-mounted exhaust fan will have a duct that runs through the ceiling, eventually terminating on an exterior wall of the home. Depending on the home’s architecture, a wall-mounted bathroom exhaust fan will have a duct that runs to the adjacent exterior wall or up the interior wall, under the floor or above the ceiling, finally ending at an exterior home wall. It’s essential that bathroom exhaust ducts vent outside the home and not into the attic, basement, or other interior space. That would effectively channel hot, humid air into a space that is not typically climate controlled. That is practically begging for mold problems.

Signs That Your Bathroom Exhaust Fan Motor Needs Replacement

A failing exhaust fan is one of the more common bathroom issues homeowners encounter. Here are signs that there’s trouble:

The fan has gotten louder or changed in pitch.

You’re probably familiar with your bathroom fan’s steady hum. You will probably notice if one day you switch the fan on and it sounds different than usual. That is a sign that the motor is soon to go. If the bearings are worn or some internal part is loose, you might hear a whining, rattling, or different pitch. 

Your bathroom remains damp or humid even with the exhaust fan engaged.

If you’re in the habit of routinely switching on the exhaust fan during a shower but lately your bathroom feels more humid, the fan is clearly losing efficiency. This could be a sign that the fan is rotating at a slower rate or even intermittently, limiting the extent to which it can draw away air through the ventilation duct. 

Your bathroom smells musty or stuffy.

A bathroom fan’s circulatory action keeps the room smelling as fresh as possible. If your bathroom suddenly feels stifling or musty, there is a lack of circulation. The exhaust fan is the likely culprit, and a bad motor is almost always the reason for exhaust fan malfunction. Musty odors could also be due to stubborn mold and mildew growth, which can also be a signal that your exhaust fan is not working at its optimal capacity.

The fan emits a burning smell or acrid odor when turned on.

A burning smell is an obvious sign of imminent malfunction. If you detect the smell of smoke or burning plastic when you switch on your bathroom’s exhaust fan, turn it off immediately. That is a sign that the motor is working too hard because its internal components have worn down.

The fan rotates more slowly.

If you can observe the spinning action of the fan blades behind the vent, you may notice that the fan is spinning more slowly than usual. While that could be due to mechanical wear and tear in theory, the more probable explanation is that the motor is on its way out. It may not have the power to rotate the fan as quickly as necessary.

Common Causes of Bathroom Exhaust Fan Motor Failure

Exhaust fan motors are generally reliable, but they are susceptible to failure, just like any other home appliance. Here is why your bathroom’s exhaust fan motor might break down:

• Overuse. Using your bathroom fan too frequently and for long stretches can lead to premature failure. Prolong the motor’s lifespan by using the fan only when ventilation is necessary.
• Excess humidity. Exhaust fans are designed to function in humid environments, but the ambient moisture takes its toll. Ironically enough, if you neglect to run the fan and thereby maintain a humid environment, the fan motor may have a shorter lifespan because it is in prolonged contact with humid air. This causes rust, corrosion, and potential electrical issues.
• Worn components. Fan motors will fail when internal components begin to wear down. Deteriorating bearings in particular are common culprits for motor malfunction.
• Electrical problems. Corroded wiring and power surges can fry an exhaust fan motor, rendering it inoperable.
• Obstructions. With infrequent use, exhaust fans can accumulate dust, mold, and fine debris. Excess material can gradually obstruct moving component parts, overtaxing the motor and causing premature failure.
• Overheating. Poor architectural design can put an exhaust fan motor in a position where it is continually exposed to high temperatures. The motor itself generates heat, and if it gets hot enough, it will eventually break down.
• Improper installation. There’s always the chance that the exhaust fan was installed incorrectly. Even if it seems operable for many weeks or years, an early breakdown can be the result of inexpert installation.
• Inadequate maintenance. Exhaust fans require minimal maintenance, but you shouldn’t ignore them completely. Clean your exhaust fan of dust and debris to keep it running smoothly for as long as possible.

When to Repair vs. Replace the Exhaust Fan Motor

So, your bathroom’s exhaust fan has broken down. Do you repair it by replacing bathroom exhaust fan component parts? Or do you replace the appliance entirely?

Most technicians recommend opting for targeted repairs if the appliance isn’t very old, if the replacement parts are reasonably inexpensive, or if the issue requires an easy resolution. Ultimately, it’s a cost analysis. A few bucks to replace a bearing or a little elbow grease to rid the fan of accumulated grime is well worth the investment if you get another several months or a couple years out of the exhaust fan. And a reasonably new fan is probably worth repairing, but make sure you determine why it failed in the first place.

If, on the other hand, your exhaust fan is many years old and suffering from frequent malfunctions, consider the sunk cost fallacy. It is probably better to cut your losses and replace the device entirely.

Of course, an in-the-know technician can help you make the correct decision, and if you have home warranty coverage through Liberty Home Guard, you can get access to some of the most experienced and knowledgeable home professionals in your neck of the woods. Call our team at (833)-547-6493 to learn more about our home protection plans and how we can support every one of your essential home appliances and systems.