Where the filter is and what you need before you start

Most refrigerator water filters sit in one of three places: inside the fridge at the top back corner, under the sink in the cabinet, or on the exterior back wall. Open your fridge and look at the ceiling or upper corners first — if you see a cylindrical cartridge with a blue or white plastic cap, that is your filter. If not, check under the sink for a filter housing attached to the cold water line. If neither is there, look at the back of the fridge where the water line enters.

Before you touch anything, turn off the water supply to your refrigerator. Most fridges have a small shut-off valve under the sink or behind the fridge where the water line connects. Turn it clockwise until it stops. This prevents water from spraying when you remove the old filter. You will also need a new filter cartridge that matches your fridge model — the model number is usually on a sticker inside the fridge or on the back panel.

Key Takeaways

  • Turn off the water supply before removing any filter to prevent water from spraying into your cabinet or fridge.
  • Locate your filter by checking the top back corner of the fridge, under the sink, or on the exterior back wall.
  • Buy a replacement filter that matches your refrigerator model number, not just your brand name.
  • After installing the new filter, run water through the dispenser for 30 seconds to remove air from the line.

Removing the old filter from inside the fridge

If your filter is mounted inside the fridge, locate the plastic cap at the end of the cartridge. Grip the cap firmly and turn it counterclockwise — most filters unscrew rather than pull straight out. As you turn, water may drip, so have a towel ready. Once the filter loosens, continue turning by hand until it comes free. Some water will spill into the tray below, which is normal.

After the old filter is out, look at the empty housing. You may see a rubber gasket or O-ring around the opening — this seals the new filter. If the gasket looks cracked or dried out, you can replace it, but most people leave it alone unless water starts leaking. Wipe the inside of the housing with a clean cloth to remove any sediment or debris before inserting the new filter.

Removing the old filter from under the sink or exterior wall

If your filter is mounted under the sink or on the back exterior wall, you will see a cylindrical housing with the filter cartridge inside. Locate the bowl wrench or filter key that came with your fridge — this is a plastic tool that fits over the filter housing. If you do not have it, you can buy one at any hardware store for a few dollars, or use an adjustable wrench. Place the wrench over the housing and turn counterclockwise to loosen it.

Once the housing is loose enough to turn by hand, continue unscrewing it until it comes free. Water will drain into a bucket or pan below — place one there before you start. After the old housing is off, empty any remaining water from the connection point. Inspect the rubber gasket on the housing itself. If it is cracked or hard, replace it before installing the new filter. Wipe the connection threads clean with a cloth.

Installing the new filter

For filters that screw into the fridge interior, remove the new filter from its packaging and check that the rubber gasket is in place at the base. Insert the filter into the empty housing and turn the cap clockwise by hand until it is snug. Do not over-tighten — turn until you feel resistance, then stop. Over-tightening can crack the plastic or damage the gasket.

For filters that mount under the sink or on the exterior wall, apply a thin layer of food-grade silicone grease to the rubber gasket on the new filter housing. This helps create a watertight seal. Screw the housing into the connection point by hand first, then use the wrench to tighten it another quarter turn. Again, snug is enough — you do not need to force it.

Turning the water back on and flushing the line

Once the new filter is installed, turn the water supply back on by rotating the shut-off valve counterclockwise. Turn it slowly so air does not get trapped in the line. You should hear water flowing into the filter housing. Wait 30 seconds, then use the water or ice dispenser on your fridge to run water through the system for another 30 seconds. This flushes air out of the line and removes any loose carbon particles from the new filter.

The water may look cloudy or taste slightly off for the first few uses — this is normal and will clear within a few hours. If water leaks from the connection point after you turn the supply back on, turn it off again and tighten the housing another quarter turn with the wrench. If it still leaks, the gasket may be damaged and you may need to replace the filter.

When to replace your filter and common problems

Most refrigerator filters need replacement every six months, though this depends on your water quality and how much water you use. Your fridge may have a filter indicator light that turns red or blue when replacement is due — check your manual to see what colour means replace. Some people replace on a schedule instead, marking the date on a calendar when they install a new filter.

If water stops flowing from the dispenser after you install a new filter, the filter may be installed backwards or the air lock may not have cleared. Turn off the water, remove the filter, and check that the inlet and outlet ports are aligned correctly — your manual will show which way the filter goes. Reinstall and flush again for a full minute. If water still does not flow, the filter may be defective and you should try a different brand or contact the manufacturer.

Frequently Asked Questions

Do I need to turn off the water before changing the filter?

Yes. Turning off the water prevents it from spraying when you remove the old filter and keeps water from flowing into your cabinet or fridge while the housing is open. The shut-off valve is usually under the sink or behind the fridge where the water line enters.

What happens if I install the filter backwards?

If the filter is backwards, water will not flow through the dispenser or ice maker. Remove the filter, check the inlet and outlet markings in your manual, and reinstall it the correct way. Most filters are clearly marked with arrows showing the direction of water flow.

Can I use a generic filter instead of the brand-name one?

Yes, as long as it matches your refrigerator model number. Generic filters work just as well and cost less. Check the model number on your fridge and search for compatible filters — you will find many options that fit the same housing.

Why is my water cloudy after I change the filter?

New filters release loose carbon particles into the water. This is normal and will clear within a few hours. Run water through the dispenser for 30 to 60 seconds after installation to speed up the process.

How do I know which filter my refrigerator uses?

Find your refrigerator model number on a sticker inside the fridge or on the back panel. Search that model number plus "water filter" online, or call the manufacturer with the model number and they will tell you which filter cartridge you need.