Common Cooker Hood/Extractor Problems, Faults/Fixes And Maintenance

Common cooker hood problems

A cooker hood is primarily designed to dissipate any odors that are caused while food is being cooked. It can also help remove any airborne grease that may be created during the cooking process. This is essentially an uncomplicated system and usually cooker hood problems are restricted to issues concerning the motor, main control board, or the lighting system. Ensuring proper cooker hood maintenance is probably the best way to make sure that your appliance performs at maximum capacity without any problems. Generally speaking, there are very few cooker hood problems that are actually related to component failures. Most complaints including the ever popular complaint – “My cooker does not extract quickly enough” are usually related to cooker hood maintenance and installation issues. There are however a few issues that can crop up from time to time.



The Cooker Hood Motor Produces a Distinct Humming Noise

Usually, if the cooker hood produces a humming sound when it is switched on, it points to a problem with the exhaust fan motor. In most cases, the motor is defective and there may be shorted electrical winding present within the exhaust motor. This type of problem can also be caused when the motor shaft bearings are completely worn out and unable to perform their function. The hood motor is usually not repairable and should be changed. These issues can also inhibit the Fan Motor and Blower Motor, and they should be checked for any signs of similar damage.

cooker hood

This type of noise may also suggest the presence of an external object trapped within the Blower Wheel Housing, or the Blower wheel could be hitting the blower housing while it is turning. Turn the blower wheel manually to ensure that it is able to turn without any restrictions. If it is making contact with the blower housing, the alignment of the wheel should be corrected. You should also check the fan blade to ensure it is able to rotate freely.

If none of these steps remedy the situation, you may be dealing with a burned out motor that must be replaced.

The Cooker Hood Lights Do Not Work

When the cooker hood lights do not function, you might be dealing with a defective Light Assembly. There are no replaceable components in the Light Assembly and the entire unit will have to be replaced.

If the cooker hood lights fail to function, you can install a new bulb of the correct rating. If this does not solve your problem, you should move on to the on-off switch. If, your cooker hood utilizes halogen lamps/bulbs, they should be checked. It is not possible to judge the condition of a halogen lamp by just looking at it. They should be checked for continuity with an Ohm meter.

If the bulbs have been tested and are in working order, there may be a problem with the light socket, which is easily replaced. In case the light bulbs and socket are fine, you can check the condition of the Push Button Switch. The switch should be tested for continuity with the aid of an electrical (Ohm) meter.

The Cooker Hood Fan and Light Are Not Working

If the cooker hood fan and light do not appear to be working, this could indicate a problem with one of the switches on the appliance. You should inspect the Micro Switch, Switch Kit, Rocker Switch, Rotary Switch, and the Selector Switch for any defects. They should be checked individually for continuity with an Ohm meter. If any of these switches are defective they can be replaced.

In case your switches are in working order, and the problem persists you should disconnect the thermal fuse and check it for continuity.

You can also check the User Control and Display Board for signs of a malfunction. However problems with the control board are quite rare.

The Cooker Hood Downdraft Vent Does Not Stay Up

This type of problem will typically indicate a malfunction in the Rocker Switch or Selector Switch, and these switches should be tested to determine their status. A defective switch should be replaced.

The Cooker Hood Downdraft Vent Does Not Go Up

A problem with the downdraft vent normally indicates an issue with the Rocker Switch, which should be tested with an Ohm meter for continuity.

In certain cases, this problem could also be caused when the Drive Motor has developed a defect or has burned out. In such cases, the motor should be tested for continuity with an Ohm meter. If the motor seems to be functional, but is running slowly or appears strained it could have sustained a critical degree of wear and tear. Even though the motor is still functional, it is likely to fail soon and should be replaced before it ceases operation.

The Cooker Hood Downdraft Vent Does Not Shift Down

This problem is caused by a defective Rocker Switch that should be replaced.

The Cooker Hood Motor is excessively loud

If this noise appears to be emanating from the Drive Motor, it could indicate a problem within the motor. This component cannot be serviced and will have to be replaced if the noise is unbearable.

Noise could also be indicative of a problem within the Exhaust Fan Motor. This usually occurs when the fan motor bearings have reached a state of excessive wear. You can attempt to move the motor shaft by hand. This motor is fixed in place and should not move. If it does move, it is bound to generate noise during its normal operation. The motor bearings cannot be repaired or lubricated, and the motor will need to be replaced.

Similarly, the fan motor and blower motor should be checked to ensure that their bearings have not failed.

The Cooker Hood Keypad Is Unresponsive

If the cooker hood keypad does not appear to be functioning, it would indicate a defect within the Touchpad, User Control and Display Board, or the Main Control Board. These components should be checked for signs of a burn out. If they are damaged, they can be replaced.

The Cooker Hood Does Not Vent Any Cooker Emissions to The Outside

Inefficient venting by the cooker hood will usually point to a problem within the Fan Motor, Exhaust Fan Motor, or Blower Motor. You can visually inspect these parts while the cooker hood is operating. If any of these fan blades do not appear to be spinning, then that particular component has malfunctioned and will need to be replaced.

The exhaust fan blades should also be checked for signs of physical damage. If any of the blades are broken or loose, the appliance will lose some of its venting efficiency. In case you are dealing with a loose exhaust fan blade, you should try and tighten it. If you are unable to do so, the blade should be replaced.

If the fans are all functioning as designed, there could be some external object trapped in the blower wheel or housing. Additionally the blower wheel could be making contact with the housing as it spins. If the blower wheel cannot move freely, all blockages must be removed to ensure it is able to function properly.

Understanding the Use of Cooker Hood Filters

One of the most important components of the cooker hood is the filter. The filters are responsible for trapping any suspended grease particle (or other impurities) from the air that is released during the cooking process. This may be less of an issue when you are dealing with a vented cooking hood as any emission from the kitchen is directly transferred outside through the vent. However, it is still necessary to stop grease particles from entering the fan or motor assembly.

There are essentially 2 types of cooker hood grease filters that are commonly used; fabric filters and metallic filters. Fabric filters have a limited life span and need to be replaced on a regular basis. If they are not replaced regularly, their performance deteriorates and grease particles can pass through them and enter the cooker hood mCooker hood filter 1echanism. These filters could also prove to be a health hazard in the kitchen as they have a propensity for attracting bacterial growth.


In comparison, metallic filters can be easily cleaned in a dishwasher and are more long lasting. This type of grease filter utilizes a steel mesh to trap any grease that is present in cooking emissions. For the most part, metal filters are the better long term option for your cooker hood.

Some types of Circulation or Recirculation type cooker hoods utilize activated carbon/charcoal filters as a method of odor control. While, activated carbon is generally considered to be effective in absorbing odors and emission, recirculation cooker hoods are not always the best option. When a cooker hood is operating in this mode, emissions from the cooking process are not actually removed from the kitchen. They are simply passed over the charcoal filters before they are circulated back into the room. Over time, the performance of such a cooker hood can prove to be inadequate, especially in situations where there a large volume of emissions are released during cooking.

Settling On the Best Cooker Hood Installation Process

At the very outset it should be made clear that providing adequate venting to the outside air is a prime factor in determining the efficiency of this appliance. However, this is not the only factor that affects the performance of the cooking hood. It is always advisable to pay attention to all the installation guidelines that are provided in the product manual. This can help you make the right choices during the installation and help extract the maximum performance from the appliance. Make a list of all the factors that are important to the process before you actually install the appliance. It is important to decide the length of the hose that vents the appliance, the height at which the cooker hood is to be installed, the diameter of the vent hose, as well as the accessibility of the appliance after installation. If the appliance is installed in an inaccessible location, servicing can become impossible. Improper installation can result in performance drawbacks that can negate the very purpose for installing the cooker hood

The Importance of Selecting the Proper Cooker Hood Ducting

Although it is not completely visible, the ducting system is an integral aspect of your cooker hood installation and performance. Quite often, the cooker hood's failure to extract all cooking emissions and inability to function without noise has nothing to do with defects in the appliance. These problems may simply be caused when an improper size of ducting is used. Incorrect ducting configuration can hamper the flow of air and prevent adequate venting of the cooker hood.

Essentially, the aim of venting is to ensure that any emissions generated by the cooking process are removed from the kitchen environment and transferred outside the house quickly, quietly, and efficiently. Logic dictates that to achieve these aims it is better for the emissions to travel the shortest possible distance. The presence of any obstacles, or bends, will only make this process more tedious and will make it difficult to disperse any emissions from the kitchen quickly and efficiently. Another factor that should be considered here is the power generated by the cooker hood fans; the size of the ducting used should be based on the power generated by the hood's exhaust fan.

In general, there are a few guidelines that should be followed during the installation process that can ensure maximum extraction.


  • Always ensure that the ducting follows the quickest and most direct path to the outside of the house or to the location where the extracted air is to be released
  • As far as possible, avoid the use of bends in the ducting
  • The Duct size should be selected after analysis of the extraction capacity and size of the connectors on the hood. Never reduce the size of the ducting. Always make sure that it is exactly the same size as the cooker hood outlet.
  • Ideally, a round duct provides the best performance as air travels more easily through such ducts. Round ducts produce lower vibration, turbulence, energy loss, noise, and allows the air to pass through at a faster rate.
  • If possible, it is far more advisable to choose a rigid duct as compared to a duct that is flexible.
  • If you must use a flexible duct, ensure that it is kept as taut as possible. Also makes sure it is kept straight wherever possible.
  • Pay extra attention when you are choosing back draft dampers and wall terminals, as these devices will increase the levels of air resistance.

What Types of Ducting are Available?

In general, there are 3 types of ducting that are commonly used; Round Pipe Ducting, Flat Channel or Rectangular Ducting, and Flexible Hose Ducting.

Round Pipe Ducting - Usually, the presence of a round duct is considered to be the ideal solution where there are no space constraints. This type of ducting offers the least air resistance and venting is most effective.

Flat Channel or Rectangular Ducting - Is usually used in instances where space is at a premium. It is unobtrusive and moreover, this type of ducting may be concealed with great ease.

Ducting for cooker hood

Flexible Hose Ducting - may be rectangular or round depending on the installation requirements. This type of system is primarily used in situations where a fixed system cannot be put in place. Quite often, it may be used along with a fixed system to overcome certain problems.

Simple Cooker Hood Maintenance Procedures

Filters - One of the primary maintenance tasks is to ensure that the cooker hood filters are kept in the best possible condition. The silver, metallic grease filter is responsible for capturing airborne grease and oils and prevents them from entering the exhaust or blower vent. Cleaning this filter is a relatively simple task. Remove this filter and let it soak in a degreasing fluid for about 10 minutes. After the grease has been dissolved, you can wash the filter in a mixture of warm water and soap. The filter can then be placed in the upper dishwasher rack and put through a normal wash cycle.

If your cooker hood utilizes an activated charcoal filter, this should be changed every 3 or 4 months.

Interiors - The interior surfaces of the cooker hood may be cleaned with any commercial degreaser or cleaner. (Be sure to switch off the unit before cleaning it.) Do not apply the cleaning spray directly to the light bulb/light bulb socket.

Exteriors - The exterior surfaces of the hood may be cleaned with a degreaser/cleaner and a non-abrasive cleaning tool.

Vent Cleaning - It is also important to check the vent that connects the cooker hood to the outside to ensure that there are no build ups of grease or oil.

You should also check the blower wheel from time to time. This component can get greasy and dirty. The wheel can be removed and cleaned with a degreaser.


Disclaimer: The information provided has been prepared as a guide only and the steps taken are likely to vary for different appliance models. We strongly recommend using a qualified engineer to undertake major repairs and fault finding.


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