Replace the filter by turning off the water supply, locating the filter housing under the sink or inside the refrigerator, unscrewing the old cartridge, and screwing in a new one that matches your model number
LG water filters sit in one of two places: under your kitchen sink (for faucet-mounted or under-sink systems) or inside your refrigerator (for ice maker and drinking water dispensers). The replacement process is nearly identical either way and takes about five minutes. You do not need tools beyond your hands, though a filter wrench — a plastic tool that comes with most LG filters — makes the job easier if the old cartridge is stuck.
The most common mistake is buying the wrong filter. LG makes different cartridges for different models, and a filter that fits one refrigerator will not fit another. Before you start, find your model number on the product itself or your paperwork, then confirm the filter part number on LG's website or your filter packaging.
Key Takeaways
- LG water filters are located either under the sink or inside the refrigerator door, and you replace them by unscrewing the old cartridge and screwing in a new one by hand.
- Confirm your LG model number before buying a replacement filter, because different models use different cartridges and they are not interchangeable.
- Turn off the water supply at the shutoff valve under the sink before you remove an under-sink filter to avoid water spraying onto your cabinets.
- After installing a new filter, run water through it for several minutes to flush out carbon dust and air pockets before drinking or using it.
- Most LG filters should be replaced every six months, though this depends on your water quality and how much water you use.
Locate your filter and gather what you need
Open your refrigerator door and look for a cylindrical cartridge in the upper right corner, inside the door frame, or along the back wall. If you do not see one there, the filter is under your sink. Look in the cabinet directly below your faucet for a white or clear plastic housing, usually about the size of a soda can, connected to the water line.
Gather a new LG filter cartridge (matching your model number), a small bowl or cup to catch water drips, and a towel. If the old filter is stuck, a filter wrench will help, but most come off by hand. Do not start until you have the new filter in hand — once you remove the old one, water will begin to leak if you have not shut off the supply.
Turn off the water supply for under-sink filters
If your filter is under the sink, locate the shutoff valve on the water line coming into your home. It is usually a small knob or lever on the pipe under the sink, near the back wall. Turn it clockwise (or flip the lever perpendicular to the pipe) until it stops. This prevents water from spraying out when you unscrew the cartridge.
If you cannot find a shutoff valve under the sink, look for the main water shutoff for your entire house — typically in the basement, crawl space, or outside near the foundation. Turning off the main supply takes longer but works just as well. You do not need to shut off water for refrigerator filters because they have a small internal shutoff valve that closes when you remove the cartridge.
Remove the old filter cartridge
Place your bowl or towel underneath the filter housing to catch water that will drip out. Grip the cartridge firmly and turn it counterclockwise by hand. Most LG filters unscrew like a jar lid. If it will not budge, wrap a towel around it for better grip, or use the plastic filter wrench that came with your new filter — insert it into the notches on the cartridge and turn.
Once the cartridge is loose, continue turning until it comes free. Water will spill, so keep the bowl underneath. For refrigerator filters, you may see a small amount of water drip from the housing — this is normal. Set the old cartridge aside for recycling if your area accepts them, or throw it in the trash.
Install the new filter and flush the system
Before screwing in the new cartridge, check that the rubber gasket (the ring of rubber on the top or bottom of the cartridge) is clean and in place. Wipe the inside of the filter housing with a dry cloth to remove any debris. Screw the new cartridge in by hand, turning clockwise until it is snug. Do not over-tighten — hand-tight is enough.
Turn the water supply back on (if you shut it off) and run water through the filter for three to five minutes. You may see black specks or cloudy water at first — this is carbon dust from the new filter and is harmless. Keep running water until it runs clear. For refrigerator filters, dispense water and ice for a few minutes to flush the system.
Reset the filter indicator light on your refrigerator
Many LG refrigerators have a light that tells you when the filter needs replacing. After you install a new cartridge, this light will stay on until you reset it. Look for a small button or icon on the refrigerator's control panel labeled "Filter Reset" or "Water Filter". Press and hold it for three to five seconds until the light turns off or changes color.
If you cannot find the reset button on the refrigerator itself, check your owner's manual — some models require you to reset the filter through the touchscreen menu. The exact steps vary by model, but the manual will walk you through it. Resetting the light does not affect the filter's performance; it straightforward tells the refrigerator that you have installed a new one.
Know when to replace your filter next
LG recommends replacing water filters every six months under normal use. If you have hard water, high sediment, or use a lot of water, you may need to replace it sooner. If you use very little water, you can stretch it to nine months, but do not go longer than a year — filters lose effectiveness over time even if you are not using them.
Watch for signs that your filter needs replacing before six months: water pressure drops noticeably, water tastes or smells off, or the filter indicator light comes on. Some LG models have a smart indicator that tracks actual water usage rather than just time, so it may alert you sooner or later than six months depending on your household.
Frequently Asked Questions
What if water keeps leaking after I install the new filter?
The cartridge is not screwed in tight enough, or the rubber gasket is not seated properly. Turn off the water, unscrew the cartridge, and check that the gasket is clean and in the right position. Screw it back in firmly by hand — you should feel resistance as the threads catch. If it still leaks, the gasket may be damaged and you may need a new filter.
Can I use a non-LG filter in my LG refrigerator or sink system?
Third-party filters made by other brands sometimes fit LG housings, but LG does not recommend it. Using a non-LG filter may void your warranty and could affect water quality or pressure. Stick with LG cartridges that match your model number to be sure the filter fits correctly and performs as intended.
Where can I buy replacement LG water filters?
LG filters are sold at most big-box retailers like Home Depot and Lowe's, online at Amazon and Walmart, and directly from LG's website. Prices vary by model but typically range from $30 to $60 per cartridge. Buying in bulk or through a subscription service sometimes costs less per filter over time.
Do I need to turn off the water before replacing a refrigerator filter?
No. Refrigerator filters have an internal shutoff valve that closes automatically when you remove the cartridge, so water will not spray out. You will see a small amount of water drip from the housing, which is why you should place a towel underneath, but you do not need to shut off the main water supply.
What should I do with my old LG water filter?
Check whether your city or county accepts water filters in curbside recycling — many do not because of the plastic housing. Call your local waste management office or check their website. If recycling is not an option, throw the old filter in the trash. Do not pour the water that comes out of the old filter down the drain; it is just regular tap water.