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How to Clean and Replace Microwave Filters

Marc McCollough

By Marc McCollough
Published April 6, 2026

Leftovers can be great, but you might not appreciate leftover aromas from sauteed onions and fried fish that linger after the cooking is done. Simple steps for cleaning and replacing the filters in your microwave ventilation system help clear the air so you can enjoy the food and forget the odors.

Key Takeaways

  • A reusable grease filter on an over-the-range (OTR) microwave keeps grease spatters out of the exhaust system.
  • In an OTR microwave that recirculates air into the kitchen, a charcoal filter reduces cooking odors.
  • Follow the maintenance instructions for your microwave.
  • Unplug the microwave or turn off the breaker before starting any work.
  • To clean a grease filter, remove the filter, soak it in water and a mild detergent, then rinse, dry it thoroughly and reinstall it.
  • To replace a charcoal filter, remove the cover, swap the filter with a new one and replace the cover.
  • Reconnect the microwave to power.
  • Reset the filter indicator light, if necessary.

Microwave Filters and When to Clean or Replace Them

The filters in an over-the-range microwave exhaust system need maintenance so the system can efficiently remove smoke, odors and moisture caused by cooking. This guide explains, in general, when and how to clean and replace microwave filters but check your manual and follow the steps for your specific microwave.

Microwave Venting and Filter Types

OTR microwaves that use external venting, where the air exhausts to the outside, typically only have a reusable grease filter:

  • The grease filter keeps spatters from range-top cooking out of the exhaust system.
  • Clean the grease filter at least every month, or if you notice poor ventilation.

OTR microwaves that recirculate the air into the kitchen instead of venting it outside have a grease filter as well as a disposable charcoal filter:

  • The charcoal filter reduces cooking odors.
  • Replace the charcoal filter at least every six to 12 months, or if you notice persistent cooking odors.

Some OTR microwaves have a filter indicator light that reminds you to clean or replace a filter.

How to Clean a Microwave Grease Filter

A microwave grease filter is simple to wash by hand in just a few minutes. Here are the basic steps. A grease filter is typically on the bottom of an OTR microwave and some models might have two.

Tip

Some aluminum grease filters are dishwasher safe but check your product information before cleaning a filter in a dishwasher.

Step 1: Disconnect the Microwave From Power

  • If the microwave plugs into an outlet in the cabinet above, simply unplug it.
  • If the microwave is hardwired, turn off the breaker at the breaker box and make sure the microwave doesn’t have power.

Step 2: Remove and Clean the Grease Filter

  • Release the retention tab, if equipped, and pull the grease filter out of the housing on the bottom of the microwave.
  • If your filter has a removable frame, detach it according to the manufacturer’s instructions.
  • Place the filter in a sink basin of hot water and a couple of squirts of dish detergent.
  • Add 1/4 cup of baking soda if recommended by the manufacturer.
  • Let the filter soak for at least 10 minutes.
  • You might need to scrub the filter lightly with a soft-bristle brush.

If the filter is damaged or too dirty to clean effectively, replace it with a new filter.

Step 3: Rinse and Replace the Filter

  • Rinse the filter under clean, hot water.
  • Shake water from the filter and let it air dry completely or pat it dry with a towel.
  • If your filter has a removable frame, reinstall it around the filter.
  • Once the filter is completely dry, slide it back in place.
  • Plug the microwave in or turn the breaker on.

How to Replace a Microwave Charcoal Filter

A microwave charcoal filter isn’t washable, so you need to replace it. You’ll only find this type of filter in a microwave that recirculates air into the kitchen. Use the model number of your microwave or existing filter to find the right replacement filter.

Step 1: Disconnect the Microwave From Power

  • If the microwave plugs into an outlet in the cabinet above, simply unplug it.
  • If the microwave is hardwired, turn off the breaker at the breaker box and make sure the microwave doesn’t have power.

Step 2: Remove the Vent Cover

  • Access the vent cover and grille, if equipped, on the top front edge of the microwave.
  • Pop the cover or grille out, or, if necessary, remove the screws and slide or tilt the cover away to reach the charcoal filter.

Step 3: Replace the Filter

  • Pay attention to the orientation of the existing filter.
  • Slide the filter out and dispose of it properly.
  • Slide the new charcoal filter into place, oriented like the old one.
  • Replace the vent cover and grille and then reinstall the screws, if necessary.
  • Plug the microwave in or turn the breaker back on.

Tip

Some filters have an airflow arrow to help you ensure correct installation.

Resetting the Microwave Filter Light

If your microwave has a filter maintenance indicator light, you’ll need to reset it manually. Check your manual for instructions, but there might be a RESET FILTER button or there might be a key on the control keypad you press and hold to turn the filter light off.

Keep Your Microwave Exhaust System Working Smoothly

Maintaining your microwave filters is a simple way to reduce smoke, cooking odors and excess moisture from your kitchen. If it’s time to replace a filter, shop Lowes.com for filter kits or stop by your local Lowe’s. A Red Vest associate can help you find filters that work with your microwave and keep the exhaust filter working efficiently.

Microwave Filter FAQ

Use the answers to these common questions to make sure the exhaust system on your OTR microwave is working as efficiently as possible.

Why Is My Microwave Filter Light On?

A filter light on a microwave is often a reminder to replace the charcoal filter. The light illuminates after a specific amount of time (for example every six months) or after the exhaust fan has run for a certain number of hours. On some models, the light might be a reminder to clean the grease filter and replace the charcoal filter. Replace and clean the filters, then reset the light by pressing a FILTER button or a key on the keypad, according to the manual.

Can You Wash a Grease Filter in the Dishwasher?

You can wash some types of aluminum grease filters on the top rack of a dishwasher but check your microwave manual or the filter documentation. Manufacturers often recommend cleaning the filter by hand with hot water and a mild detergent, such as dish detergent.

How Often Should You Replace a Microwave Charcoal Filter?

You should replace the charcoal filter on a microwave every six to 12 months at a minimum. Check your manual for specifics. If the microwave FILTER light is on or you notice the filter isn’t reducing cooking odors, it’s time to replace the filter.

Can I Use My Microwave Without a Grease Filter?

No, a grease filter needs to be in place to capture grease from stovetop cooking. If grease gets into the exhaust system of a microwave, it can create a fire hazard. Grease accumulation also reduces ventilation efficiency and can cause the fan to wear prematurely.

Do All Microwaves Have Filters?

No, typically only over-the-range microwaves have filters. An OTR microwave has a system that either exhausts smoke, odors and moisture from the range to the outside, or a system that filters the air and recirculates it into the kitchen. You’ll find grease filters on most OTR microwaves and charcoal filters on those that recirculate the air.

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