Most refrigerator water filters twist or push out in under a minute, and Whirlpool, Samsung and LG all say to replace them about every six months. The step people skip is flushing: run the amount of water your manufacturer specifies (LG says about 2.5 gallons, Whirlpool says 4) before you drink from it.
What you'll need and how long it takes
Plan on 10 minutes for the swap and another 5 to 10 for flushing. You don't need tools on most fridges. Have these ready before you start:
- The correct replacement cartridge, matched to the part number printed on your old filter or listed in your manual.
- A towel to catch drips, plus a cup or shallow pan under the filter housing.
- A large pitcher or a bucket for flushing, so the water can go on plants instead of down the drain.
- Your owner's manual, or the model number from the label inside the fridge, if you're not sure where the filter is.
Know when to change it
Stick with the interval your manufacturer gives. Whirlpool says about every six months. Samsung also says six months and adds that you should change it sooner if water flows noticeably slower with the filter in than without it. LG says about every six months, or sooner if dispensing slows down or the filter indicator comes on.
Whirlpool adds that heavy use and poor water quality can mean changing it more often. A dispenser that has slowed down or a filter light that's already on are both reasons to change it early.
Find the filter and the right cartridge
Filters live in a handful of spots depending on the fridge. Whirlpool uses three main locations across its models: the upper right corner inside the fresh food compartment, behind a door in the base grille at the bottom front, and the left side of the base grille. LG's location depends on the model: on some the housing sits at the far back left of the fresh food compartment, on others along its left side. Samsung says the location varies and to check the manual.
Read the part number off the old cartridge before you order. Samsung, for example, lists three filters (HAF-CIN, HAF-QIN and HAFCU1) and says to check the number on the one you have. It also recommends genuine Samsung filters only and warns that third-party cartridges can leak.
GE is a special case. Its bottom-freezer models with an LCD touch screen that take the RPWFE filter read an ID chip under the filter's label to track filter status and watch for leaks. GE says a filter with no chip isn't a genuine RPWFE and won't work in those fridges, so a cheap lookalike is money wasted on these models.
Shut the water off and relieve the pressure
Samsung tells owners to turn off the water supply before removing the old filter, and LG says to close the supply valve on models that need it. Even if your manual doesn't mention it, closing the valve takes ten seconds and keeps the mess small.
LG adds a good trick: with the valve closed, press the dispenser paddle for a few seconds to bleed pressure out of the line. Lay the towel under the filter housing before you start, because a few ounces of water will still come out when the old cartridge releases.
Swap the cartridge
The removal motion depends on the design, so look at the housing before you pull. Here's how the common styles work:
Remove the old cartridge and drain any water left in it into the sink.
Unwrap the new filter and take off the protective cap or the covers on its O-rings. Whirlpool says to confirm the O-rings are still sitting in their grooves.
Line up the tabs or arrow on the new filter with the housing. Whirlpool marks its cartridges with an arrow that points up or left depending on the style.
Push it in fully and turn it clockwise until it stops. On Samsung and LG twist-in filters, the lock symbol or mark lines up with the reference line on the housing when it's seated.
Close the filter door or cover until it snaps, and put back any shelf, bin or lamp cover you removed.
Open the water supply valve slowly and watch the housing for a minute or two for drips.
- Twist-in cartridges (inside the cabinet): turn the old filter counterclockwise (to the left) and pull it straight out.
- Push-in cartridges with a door (upper right or base grille): lift or open the filter door and pull the old cartridge out.
- Eject-button cartridges in the base grille: press the button and the filter pops forward.
- Handle-style LG cartridges: on some models, such as those that take the LT900X3, you turn the handle 90 degrees to the left and then pull forward. Check your manual if it doesn't move.
Flush the new filter
A new cartridge is full of air, and Samsung notes that flushing clears that air along with any impurities. Expect the first water to sputter and spit as the air works out. Run it into a pitcher, not a glass you plan to drink.
Use the flushing amount your manufacturer lists, since they differ:
- Whirlpool: run 4 gallons (about 15 l) through the dispenser.
- LG: dispense about 2.5 gallons (9.5 l), or run water 30 seconds on and 60 seconds off until you reach 5 minutes total.
- Samsung: for the HAFCU1, Samsung says to dispense several gallons to clear air and impurities. Its US page doesn't give an exact figure, so check your manual.
- Other brands: follow the instructions printed on the cartridge box or in the owner's manual.
Reset the filter light
On most fridges the reminder runs on a timer (Samsung's is set to six months), so the light stays on until you reset it. On LG fridges, hold the Water Filter or Filter Reset button for 3 seconds until you hear a chime or the light goes out. Samsung uses the same 3-second hold on its standard models. Family Hub models reset under Apps, Fridge Manager, Fridge Settings, Water Filter. Whirlpool's reset varies by model, so check the manual.
Write the date on a piece of tape on the housing. It's the easiest way to know when the next change is due if the reminder gets reset by accident.
If the dispenser won't flow after the change
The usual reason is a new filter that isn't fully locked. Pull it out, check that the caps and wrappers are all off, and seat it again with a firm push and turn. Whirlpool's check is to try the dispenser with the filter removed. If water flows then, reinstall the cartridge. A drip from the housing usually means a missing or rolled O-ring or a cartridge that isn't turned all the way. Our water dispenser guide covers the other causes.
On the GE models that use the RPWFE filter, a Leak Detected message can show up after a change. GE's advice is to check the filter area for water and make sure the cartridge is installed correctly, and it says replacing the filter clears the message in most cases. If it stays on with a genuine, correctly fitted filter, GE says the fridge needs service.
When to call a professional
Call a technician or the manufacturer if the filter housing keeps leaking with a correctly seated genuine cartridge, or if the housing is cracked. A housing that won't accept the correct filter may be damaged and need replacing.