What a Whirlpool Water Filter 4 Does and When to Replace It
A Whirlpool Water Filter 4 (also called Filter 4 or W10413645A) sits inside your refrigerator and removes chlorine, sediment, and odors from the water that feeds your ice maker and water dispenser. Most Whirlpool refrigerators with built-in water dispensers use this cartridge or a compatible equivalent.
You should replace it every six months if you use the water dispenser regularly, or when the water tastes or smells off. Some refrigerators have a filter indicator light that turns red or blue when replacement is due—check your fridge's control panel. If your model does not have a light, set a phone reminder for six months after installation so you do not forget.
Replacing the filter yourself takes about five minutes and costs between $25 and $50 for a genuine Whirlpool cartridge, or less for compatible third-party versions. You do not need tools or special knowledge—the cartridge twists in and out by hand.
Key Takeaways
- The Whirlpool Water Filter 4 cartridge twists counterclockwise to remove and clockwise to install, with no tools required.
- Before you install a new filter, run water through the dispenser for 2 to 3 minutes to flush air from the line and remove carbon dust from the new cartridge.
- The filter location varies by model: check your refrigerator's manual or the inside of the fridge door to find whether it is in the base grille, inside the fridge, or behind the crisper drawer.
- Genuine Whirlpool Filter 4 cartridges last about six months with regular use, though some third-party filters claim longer life.
Locate Your Filter Before You Start
The Whirlpool Water Filter 4 location depends on your refrigerator model. Most commonly, it sits in the base grille at the front bottom of the fridge—you may need to remove a plastic cover or grille panel to access it. Some models place the filter inside the refrigerator compartment, usually on the right wall near the top or bottom. A few models hide it behind the crisper drawer on the left side.
Open your refrigerator manual or look for a diagram on the inside of the fridge door—Whirlpool prints filter location instructions there on most models. If you cannot find the manual, search your model number (printed on the back wall or inside the door frame) on Whirlpool's website, where you can read a PDF. The model number looks like WRF535SMHZ or similar.
Once you know where the filter is, check whether you need to remove any panels or drawers to reach it. For base-grille filters, you may need to unscrew a plastic cover or pop out a clip. For interior filters, clear the shelf above or below it so you have room to work.
Remove the Old Filter Cartridge
Turn the old filter cartridge counterclockwise (to the left) by hand. Most cartridges have a knurled grip—a textured band around the middle—that makes them straightforward to turn without tools. Rotate it until it stops, then pull it straight out toward you. Some water may drip, so have a towel or small cup ready.
If the cartridge is stuck, wrap a dry cloth around the grip for better traction and try again. Do not use pliers or a wrench—you can crack the plastic housing. If it still will not budge, turn off the water supply to the refrigerator (usually a valve under the sink or behind the fridge) and wait a few minutes, then try again.
Once the old cartridge is out, look inside the housing for any loose debris or sediment. Wipe the inside of the housing with a clean, damp cloth if you see buildup, but do not use soap.
Install the New Filter Cartridge
Remove the new Whirlpool Water Filter 4 from its packaging. Some cartridges come with a protective cap on the inlet end (the end that faces into the fridge)—remove this cap before installation. Check the cartridge for any plastic wrapping or seals and remove those as well.
Insert the new cartridge into the housing by pushing it straight in until it seats fully. Then turn it clockwise (to the right) by hand until it stops. You should feel resistance as the internal seals engage—turn it firmly but do not force it. The cartridge should be snug and not wobble.
If the cartridge does not turn smoothly or feels stuck before it is fully seated, remove it and check that the inlet end is aligned with the opening. Debris or a misaligned seal can block installation. Clean the housing again if needed and try once more.
Flush the New Filter and Reset the Indicator Light
After installation, run water through the dispenser for 2 to 3 minutes without stopping. This flushes air from the water line and removes carbon dust from the new cartridge, which can make the water taste bitter or look slightly gray for the first few uses. Let the water run into a sink or bucket—do not drink it during this flush period.
After flushing, the water should run clear and taste normal. If it still tastes off after 5 minutes of running, the cartridge may be defective—contact Whirlpool or the seller for a replacement.
If your refrigerator has a filter indicator light, reset it now. Most models require you to hold a button labeled "Filter Reset" or "Water Filter" on the control panel for 3 to 5 seconds until the light changes color or turns off. Check your manual for the exact method, as it varies by model. If you skip this step, the light will continue to show red or blue even though the filter is new.
Troubleshooting Common Installation Problems
If water leaks from the filter housing after installation, the cartridge may not be seated fully. Turn off the water supply, remove the cartridge, and check that the rubber seals inside the housing are clean and not cracked. Reinstall the cartridge and turn it clockwise until you feel firm resistance. Turn the water back on slowly and watch for leaks for a few minutes.
If the water pressure from the dispenser drops noticeably after filter replacement, the new cartridge may be clogged or installed backward. Remove it and check that the inlet end (usually marked with an arrow or "IN") faces into the fridge. If pressure is still low after reinstalling correctly, the cartridge may be defective—try a replacement.
If the water still tastes like chlorine or smells bad after flushing, the old filter may have been overdue for replacement and the line may contain trapped sediment. Run water for another 5 to 10 minutes. If the taste does not improve, the cartridge may be faulty or your water supply may have a separate issue unrelated to the filter.
Genuine Whirlpool vs. Compatible Filters
A genuine Whirlpool Water Filter 4 (model W10413645A or equivalent) costs $35 to $50 and is may provide to fit your refrigerator. Whirlpool stands behind these cartridges and will replace them if they fail within the warranty period.
Compatible third-party filters cost $15 to $30 and work in the same housing. They filter water the same way, but some brands claim longer life (9 or 12 months instead of 6) without independent verification. If you choose a compatible filter, buy from a reputable seller and check the return policy in case it does not fit or perform as expected.
Both types install the same way. The choice comes down to budget and whether you prefer the certainty of a Whirlpool-branded cartridge or are willing to try a less expensive alternative.
Frequently Asked Questions
Can I use a Whirlpool Water Filter 4 in a different brand of refrigerator?
No. The Whirlpool Water Filter 4 is designed specifically for Whirlpool refrigerators and will not fit other brands. If you have a different refrigerator, check your manual or contact the manufacturer to find the correct filter model.
What happens if I do not replace the filter?
The cartridge will become clogged with sediment and chlorine over time. Water will taste worse, the dispenser pressure may drop, and the filter will stop removing contaminants. Continuing to use an overdue filter does not damage the refrigerator, but the water quality suffers.
Do I need to turn off the water supply before replacing the filter?
No, not for most models. The filter housing has an internal valve that stops water flow when you remove the cartridge. However, if water leaks heavily when you remove the old filter, turn off the water supply valve (usually under the sink or behind the fridge) and wait a minute before continuing.
Why does the water taste bad after I install a new filter?
New cartridges contain carbon dust from manufacturing. Running water through the dispenser for 2 to 3 minutes flushes this dust out. If the taste does not improve after 5 minutes of flushing, the cartridge may be defective or your water supply may have a separate issue.
How do I know which Whirlpool filter model I need?
Check your refrigerator manual or search your model number on Whirlpool's website. The manual will list the correct filter. If you are unsure, you can also remove the old cartridge and look for a model number printed on it, then search that number to confirm it is a Filter 4 or compatible equivalent.