A range hood is an essential kitchen appliance that helps keep your kitchen clean, smoke-free, and well-ventilated while cooking. It’s designed to suck up smoke, steam, and cooking fumes and release them outside your home.
However, what if you wake up in the middle of the night to the sound of your range hood turning on itself?
It can be a startling and confusing experience that raises several questions in your mind. Is it a sign of a malfunctioning appliance? Is there a ghost in your kitchen? Or is there a more rational explanation for this phenomenon?
In this article, we’ll explore the possible causes of a range hood turning on by itself and what you can do to troubleshoot the issue. So, let’s dive in and unravel the mystery of the rogue range hood!
Why Does My Range Hood’s Fan Turn On By Itself?
Some range hood models have a sentry function that monitors the air temperature above the cooktop. As soon as the sentry system detects too much heat, the exhaust fan turns on to assist in cooling the cooktop area.
There can be several reasons why the range hood fan becomes activated when the cooktop area is at room temperature, including a faulty temperature sensor, loose wiring, or a malfunctioning electronic control board.
In the sentry system, the temperature of the air is monitored using a temperature sensor.
Use a multimeter to check the resistance of the temperature sensor if the fan runs when the cooktop area is at room temperature.
The range hood’s tech sheet will provide a temperature/resistance chart, and if the resistance of the temperature sensor does not match this estimated value, it should be replaced.
Connect any loose wires that may be near the temperature sensor if the sensor’s resistance is okay.
The electronic control board is not correctly detecting the temperature sensor’s signal if the wiring is okay.
Understanding The Reasons Behind Range Hood Turning On By Itself
Despite experiencing a problem with a range hood that starts turning on by itself, it’s reassuring to know that it can be fixed easily.
1. The Range Hood Can Turn On By Itself For Its Remote Control
The new remote control feature makes it convenient for homeowners to operate their range hood anywhere they are in the house. This means the range hood will turn on automatically without any manual adjustment.
Maybe this happened because the remote control was under stress. It can be quickly done if you have children in your household with access to the range hood’s remote control.
2. The Temperature on Your Cook Top Is Too High When Not in Use
Has your stove been left on after you finish cooking? Has your kitchen caught on fire? To cool down your room, your range hood will ask itself all these questions before turning on its exhaust fans.
Several models include temperature sensors to detect when the cooktop is too hot. During the day, high temperatures can occur in some kitchen configurations (especially those with a lot of windows).
The range hood might think that direct sunlight is cooking heat and turn on without any apparent purpose if your cooktop is constantly exposed to direct sunlight.
Solution
To prevent heat buildup during the day, you should cover your cooktop with a damp cloth for a few hours before using it. Hopefully, this will prevent its exhaust fans from being activated incorrectly.
3. It Could Be Due To A Malfunctioning Switch Or Timer Feature
In most cases, this is caused by a malfunctioning switch or timer. Generally, range hoods are equipped with switches, timers, or motion sensors for controlling fan speed.
A failed temperature sensor can sometimes cause the range hood to turn on unexpectedly. This is why not only can your range hood be turned off, but it can turn off solely by itself.
How To Fix This?
In order to fix this situation, it’s essential to identify whether the issue is with the switch, timer or motion sensor.
The switch may just need to be reset per instructions in your appliance manual, or you may need to contact the manufacturer for more help if it is an automatic switch.
Additionally, the timer could be set incorrectly, leading to unexpected behavior. In addition, you can modify this setting accordingly.
4. There’s an Error in Communication Between the Primary Circuits
There might be something wrong with the inner circuits of your range hood. A technician has said that 99% of all electronic device problems can be solved by restarting them.
A simple task like disconnecting and reconnecting your range hood could solve the problem. Your range hood might suddenly turn on or off if its primary circuit is having trouble communicating with the rest of the circuit board.
There is a chance that this may occur, but it is pretty rare.
Solution
It’s an effortless and quick procedure, very similar to restarting an Internet modem. After unplugging the range hood and waiting 30 seconds, plug it back in.
It seems like an obvious fix, but how often this resolves the autonomous activation-deactivation problem would be surprising.
5. The Temperature Sensor Is Responsible Most Of The Time
It is common for range hoods to activate automatically when they detect a certain amount of heat coming from the stovetop using a sentry feature.
Due to a range hood’s primary purpose, smoke, steam, and other airborne particles are captured from cooking.
For this to be effective, it must know when the stove or oven is in use to turn it on whenever necessary.
The temperature sensor is at the heart of this process and helps detect how much heat your stovetop or oven produces.
An internal fan motor and temperature sensor work together to control the range hood’s on-off cycle.
Therefore, a malfunctioning sensor will prevent the range hood from turning on. Depending on the situation, you may experience reduced airflow, increased smoke and steam in your kitchen.
Generally, range hoods turn on themselves due to this reason.
How To Fix It?
Sensors are packed with transistors and connections. A faulty sensor cannot be repaired by anyone who is not a specialist.
A specially skilled person would have a difficult time fixing it. In this case, I recommend you replace the sensor. If you need this information, you can contact the manufacturer.
What To Do If Range Hood Fan Turns On By Itself?
A communication error between the primary electronic circuit board and the control electronics might be the culprit if the hood turns on by itself.
- Disconnect the hood from its power source.
- Plug it back in after waiting 30 seconds.
- Also, you may find the power switch and follow the same steps.
- Check if your remote control is malfunctioning.
- Check if the batteries need to be replaced.
- Replacing the remote control may resolve the problem, so remove and check the batteries.
- Check for nearby wireless devices and strong light sources (e.g., cordless phones or direct sunlight from windows) that might cause interference.
You may want to contact the Authorized Service Center if this does not resolve the problem.
Is Your Range Hood Ignoring The Power Switch And Staying On All Day?
Are you having problems with your range hood staying on all day? Electronic control boards are usually to blame for this problem, which is very serious.
Your range hood may not turn off properly if it ignores the power switch and does not respond to it. A good solution is to replace the control board or the power button.
It is necessary to unplug the range hood from its socket first before you begin repair work so that no electricity can flow through it.
Something else might be causing your problem if this doesn’t resolve it. Replacing the electronic control board is an excellent first step in figuring out what’s wrong.
Do Range Hood Exhausts Use A Lot Of Electricity?
This depends on several factors, including the range hood model you own. At what frequency do you use it? When the circuit fails and stays on longer than usual due to a technical problem.
Although range hoods consume a certain amount of power, they usually don’t use up much power on their own.
Their average power consumption is between 100-150 watts when activated. Considering this, an average refrigerator runs continuously at a power consumption of approximately 700 watts!
Although you should always follow safety precautions when working with household appliances. You don’t need to worry about your range hood consuming too much electricity.
Final Words
Sometimes, the most sophisticated range hoods cause the most problems, as crazy as that may sound. Unlike most other appliances, these appliances react to environmental changes within milliseconds.
A negative outcome is not necessarily the best outcome. It’s better to have a reliable range hood that operates even when I’m not using it than one that fails when I’m in trouble!
