A refrigerator water filter sits inline on the supply to the dispenser and ice maker. It uses carbon block filtration to remove chlorine, sediment and some contaminants. Over time the carbon is exhausted and the filter stops doing anything useful — while continuing to restrict flow and, eventually, becoming a place where bacteria can grow.

Changing it is one of the simplest appliance maintenance jobs there is, provided you have the right cartridge and you know the flush procedure.

When to change it
  • Every six months for most households.
  • Every 200 gallons if you use a lot of dispensed water.
  • Sooner if the flow drops noticeably, the water tastes or smells off, or the filter indicator light comes on.
  • Immediately after moving into a new home, since you cannot know the filter's age.
  • Not on the indicator light alone — it is usually a six-month timer, not a flow sensor.

On this page

  1. Change interval and why
  2. Find the right cartridge
  3. Filter types
  4. Step-by-step replacement
  5. Flushing the new filter
  6. If you do not want to keep buying filters
  7. FAQ

Change interval and why

ConditionChange at
Two-person household, average use6 months
Heavy dispenser useEvery 4–5 months, or at 200 gallons
Light use, one person6 months anyway — time degrades carbon too
Hard, chlorinated municipal water6 months or sooner
Well water with sedimentSooner; consider a pre-filter
Noticeable flow drop or taste changeImmediately
New home, unknown filter ageImmediately
Why time matters as much as volume

The carbon block does not only become saturated through use. Once wetted, it provides a damp, nutrient-rich surface, and after about six months it can support bacterial growth. That is the reason for the time-based interval, not just a litres-based one.

Find the right cartridge

  1. Note the fridge model number from the interior plate.
  2. Look at the old cartridge — the number is printed on its body, and it is the fastest route to an exact match.
  3. Check the filter housing for a brand and model designation.
  4. Search the model number plus 'water filter' on the manufacturer's parts portal.
  5. Beware of 'fits your model' listings that show a generic cartridge; check the part number against the manufacturer's list.
  6. Buy certified filters with NSF/ANSI 42 and 53 certification where the brand claims it.

Filter types

TypeHow it fitsNotes
Twist-in (bayonet)Turn a quarter turn to releaseMost common on modern fridges
Push-in (PUSH)Grip and pull straight outSome Fisher & Paykel and others
Inline (compression)Cut into the supply lineOlder and under-sink style
Drop-in cartridgeSits in a housing you openCartridge only, housing retained
Internal + inline comboTwo filtersFollow the manual for order

Step-by-step replacement

  1. Locate the filter. Usually inside the fridge compartment at the top right, behind the crisper, or in the grille at the bottom front.
  2. Place a towel under the housing. There will be a small amount of water, always.
  3. Turn off the ice maker if your model has a switch, so it does not try to run dry.
  4. Twist-in type: turn the cartridge a quarter turn anti-clockwise and pull it out.
  5. Push-in type: grip the cartridge and pull straight out.
  6. Remove the protective cap from the new cartridge and note the orientation.
  7. Insert the new cartridge and twist until it stops, or push until it clicks.
  8. Wipe up the spillage and check for drips around the housing.
  9. Reset the filter indicator — usually a button, or a three-second press on a dispenser control.
  10. Flush the system as described below before drinking the water.
Always flush a new filter

New carbon cartridges release fine black carbon dust for the first few litres. Every manufacturer requires a flush — typically two to three gallons through the dispenser, discarding the water. Skip it and you will find carbon grit in the first glasses and in the ice maker.

Flushing the new filter

  1. Run the dispenser and discard the water — two to three gallons, or five minutes of continuous flow.
  2. Check the water clarity. It should run clear; grey or black cloudiness means more flushing is needed.
  3. Run the ice maker through two full batches and discard the first batch or two. Ice made immediately after a change contains the same carbon dust.
  4. Check for leaks at the housing after the first hour.
  5. Taste the water — it should be neutral. A persistent odd taste usually means the wrong cartridge or an airlocked line.
  6. Log the date on the filter or in your phone so the next change is not a guess.

If you do not want to keep buying filters

  • A bypass plug — most brands sell one that replaces the cartridge so the dispenser keeps working unfiltered.
  • An under-sink system — cheaper per gallon over time and filters drinking water at the tap as well.
  • A pitcher or faucet filter — if you mostly drink from one tap, this is cheaper than fridge cartridges.
  • Keep the ice maker fed — a bypass plug maintains ice production; simply removing the cartridge may not.
  • Check your water report before deciding — if your supply is already good, the case for expensive cartridges weakens.
Replacement refrigerator water filter cartridge

Refrigerator water filter — match the number on the old cartridge

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Change every six months. The old cartridge carries its own part number, which is the fastest way to the correct replacement.

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Bottom line

Change the filter every six months or 200 gallons, buy by the number printed on the old cartridge, and flush two to three gallons through the dispenser plus two batches of ice before drinking. A filter left in place for years does nothing useful and eventually does harm.

Frequently asked questions

Common filter numbers and how they map

Filter codeFitsNote
Everydrop 1–6Whirlpool, Maytag, KitchenAidNumber determines the model
PureSource / UltraWFFrigidaire, ElectroluxSeveral generations
MWF / XWFGE and GE ProfileDifferent housings
HAF-CIN / DA29SamsungCheck the prefix
LT seriesLGLT500P, LT700P and others
WF seriesVariousCheck the compatibility list

Filter codes are family names, not universal parts. Everydrop 1 through 6 are all Whirlpool-family cartridges, but each fits a different set of models, and fitting the wrong number either will not seat or will not seal. The same applies to GE's MWF and XWF, which look similar and are not interchangeable.

The safest route is always the number printed on the cartridge you are removing. It is exact, it is unambiguous, and it removes any need to interpret a compatibility table.

How often should I change my refrigerator water filter?
Every six months, or every 200 gallons of dispensed water. Time matters as well as volume, because a wetted carbon filter can support bacterial growth after around six months.
How do I know which water filter my fridge needs?
The number is printed on the old cartridge itself, and the fridge model plate narrows it down. Search the model number plus 'water filter' on the manufacturer's parts portal to confirm.
Do I need to flush a new refrigerator water filter?
Yes. Run two to three gallons through the dispenser and discard two batches of ice. New carbon cartridges release fine black dust that you do not want in your first glass.
What happens if I do not change the water filter?
The carbon becomes exhausted so it stops removing chlorine and contaminants. Flow drops, taste degrades, and the cartridge can become a site for bacterial growth.
Can I use my fridge without a water filter?
Most brands sell a bypass plug that lets the dispenser and ice maker run unfiltered. Simply leaving the housing empty may not keep the ice maker working.