Panasonic Bathroom Fan Won’t Turn Off: Reasons And Troubleshooting

Malfunctioning humidity sensors, wiring, issues, etc. are some of the reasons why your Panasonic bathroom fan won’t turn off. 

Yes, such fans are designed to run non-stop to meet the continuous ventilation requirement but you should be able to turn it off either automatically or manually.

If not, there is trouble and this article should help you out. Stay with me for a while.

Why Your Panasonic Exhaust Fan Won’t Turn Off?

Panasonic Bathroom Fan Won't Turn Off

Such a scenario appears with cheap exhaust fans. And bath fan from Panasonic is not such fans. But when it gets old, it’s not immune to such problems.

Here are some possible reasons why is your Panasonic bathroom fan keeps running:

  • Defective Humidity Sensor

The humidity sensor is responsible to turn the exhaust fan on automatically whenever it senses a certain level of humidity in the bathroom.

It’s a great feature to keep your bathroom mold-free! But such sensors can get damaged within the first few years or it was not adjusted properly in the first place. 

When any humidity sensing bathroom fan won’t turn off, it’s usually due to the defective humidity sensor. It will send the false reading to the fan controller. 

Among many issues, a defective humidity sensor may run non-stop or may turn on the fan when it does not need to. 

It happens a lot to cheap bathroom fans but it’s very rare to Panasonic. And don’t forget— any exhaust fan will keep running if your bathroom is exceptionally humid all the time!

But it’s a good time to check the humidity sensor and make sure it’s functioning properly. 

  • Faulty Wall Switch

One of the most common and easiest problems to diagnose is an issue with the wall switch that controls your Panasonic bathroom fan.

Wall switches can suffer from loose connections, corrosion, or overall wear after extended use. This can lead to a switch that seems like it’s turning the fan off but isn’t fully deactivating the circuit.

You can test if the wall switch is the underlying problem in just a few minutes:

  1. Turn the bathroom fan on by flipping the wall switch.
  2. Listen and feel that the fan is running and exhausting air as expected.
  3. Flip the wall switch to the off position.
  4. Check if the fan shuts off completely or continues humming and running.

If the fan stays on even with the switch in the off position, this points to a problem with the switch itself.

Replacing the wall switch is a relatively easy DIY fix:

  1. Turn off the power to the switch at the breaker panel.
  2. Unscrew and remove the faceplate from the switch.
  3. Detach the wires from the faulty switch. Take note of their positions.
  4. Install the new switch and reconnect the wires to the same terminals.
  5. Screw the faceplate back on and test the fan by toggling the switch several times.

This should resolve any issues caused by a bad wall switch. Just take proper safety precautions when working with electrical wiring. Toggling the breaker off avoids getting shocked.

If replacing the switch doesn’t solve the problem, then the issue likely lies elsewhere in the wiring.

  • Problems with Fan Controls
installing panasonic bath fan

The controls inside the Panasonic bathroom fan can also malfunction and cause the fan to run nonstop. These controls include:

  1. Fan relay
  2. Speed control
  3. Motor capacitor
  4. Humidity sensor

The relay acts as a remote switch to turn the fan on and off. Speed controls set the fan’s airflow levels. The capacitor provides an energy boost to the motor. And a humidity sensor automatically turns the fan on when moisture is detected in the air.

Issues with any of these controls can override the wall switch and keep power flowing to the fan motor.

Testing and replacing fan controls requires removing the fan housing to access internal parts:

  1. Shut off power to the fan.
  2. Take down the fan unit and open the housing.
  3. Inspect controls like relays and capacitors for damage.
  4. Use a multimeter to test components.
  5. Replace any faulty parts with manufacturer recommended parts.

Replacing basic parts like the relay or capacitor is very doable. But testing and troubleshooting electronics requires knowledge of HVAC systems. Calling a technician may be the best option if you’re unfamiliar with fan motor components.

  • Problems with Fan Motor

Finally, the issue preventing your Panasonic bathroom fan from powering down may be within the fan motor itself.

Motors can suffer from burnt out windings, dislodged rotors, and seized bearings after years of use. Any of these motor malfunctions can disrupt normal on/off operation.

The motor will need replacing if it is causing the fan to stay on indefinitely. Signs of a faulty motor include:

  1. Loud grinding or buzzing noises
  2. Fan not starting or stopping intermittently
  3. Fan speed slowing down over time
  4. Burnt odor coming from fan housing

Replacing the motor requires disassembling the fan housing and will involve some rewiring:

  1. Turn power off at the breaker.
  2. Detach fan from ceiling and open housing.
  3. Disconnect and remove old motor.
  4. Install new motor matched to your fan model.
  5. Rewire motor to power supply and controls.
  6. Reassemble fan housing and test operation.

Motors do require exact replacements matched for voltage, RPMs, etc. A technician can ensure the right replacement motor is sourced and properly installed.

  • Malfunctioning Circuitry/Wiring

If the humidity sensor is okay but your fan is running non-stop, it may be due to the wiring issue. For a new exhaust fan, it can still malfunction if it’s not wired correctly.

Almost all the Panasonic fans come with switches to control the fan and light. Assuming you have tried these switches to turn it off but it’s still running, you may have a tripped GFI.

When the fan is miswired, it will trip the GFI. Try replacing the GFI. If it does not work, try changing the switch that’s operating the fan as well.

Many have fixed their non-stop fans just by changing the switch!

  • Is it A Continuous Fan?

Some exhaust fans are continuous in nature. Meaning they will keep running consuming very low electricity and making almost no noise. 

So, that’s something you should be aware of. If yours is a continuous fan, nothing to worry about. Leave it running. 

But how do you know whether it’s a continuous fan or not? 

Well, if your electricity bill suddenly gets higher and the fan is making noise, then it’s not a continuous fan!

How To Turn-off Non-stop Panasonic Exhaust Fan?

installing bathroom fan

So far I have talked about some possible reasons responsible for the continuous operation of the fan. 

You can fix the sensor, change the switch, or replace GFI to fix it. However, not everyone is handy enough to make such changes themselves. 

If you are one of them, call a professional electrician. But before you call the electrician, you should try to turn the fan off first using the HVAC system.

If your house has an HVAC system installed, there is an override control for sure. Find that control panel (which is usually near the thermostat) and you should find a setting to turn off the fan.

You still have an option even if you have no such override control mechanism. Not often but in the electrical panel, such exhaust fans have a dedicated circuit and breaker sometimes. 

Usually, you can control that panel with a single switch and use it to turn off your fan as well.

Editor’s Opinion

Panasonic has many models of exhaust fans with lots of features for your bathroom. If it is meant to run continuously, let it run.

Yes, it will consume electricity, but that’s very low. Remember, such fans are extremely energy-efficient!

And the value of clean and fresh air in the bathroom is simply priceless.

Frequently Asked Questions (FAQs)

Why is my bathroom fan not turning off?

Due to the damaged humidity sensor or malfunctioning circuitry/wiring, your bathroom fan may not turn off.

Should bathroom fan be on all the time?

Some of them are designed to run continuously but you should turn it off during the night. Most experts recommend keeping it running for 30 minutes before and after you take a shower.

How do I turn off Broan SmartSense?

Broan SmartSense has a vacation mode. You can enable that mode if you are leaving the house for a couple of days. Besides, you can press and release the SET button twice to exit the program mode. That will turn off the master control and exit the program mode.

Is leaving a bathroom fan on a fire hazard?

If you leave it on for a long time when nobody is inside the home, that can be problematic. Besides, if the fan is making noise, it can indicate the motor is malfunctioning. That can lead the motor to overheat and become a fire hazard.

How long can a fan run continuously?

All the modern exhaust fans can run for at least 8 hours continuously without causing any trouble.

Why does my bathroom exhaust fan keep running?

If your bathroom fan stays on continuously, it’s typically due to power still reaching the fan motor when it should be off. Causes include a bad wall switch, wiring problems, malfunctioning internal controls, or issues with the motor itself.

Closing Remarks

When your Panasonic bathroom fan keeps running or won’t turn off at all, don’t panic and keep calm. Use the override controls from the HVAC system and turn off the light and fan.

Any electrical task should be left to the electrician. Unless you are that electrician, call one.  

Clyde Mitchell

I run a hardware store nearby Court Anaheim, CA. Over the last 7 years, I have been blogging about home improvement and yes, I own ReliefInBath.com From me and this website, you can expect some useful tips on great ideas for a modern bathroom.

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