How to Change Your Whole House or Undersink Water Filter

(scroll down to see undersink water filter instructions)

How to Change Your Whole House Water Filter

Whole house water filters—also known as point-of-entry filters—help reduce sediment, chlorine, and other contaminants from the water entering your home. To maintain clean, safe water and protect your plumbing and appliances, filters should typically be replaced every 3 to 6 months, depending on water quality and system usage.

Step-by-Step: Changing Your Whole House Water Filter

1. Turn off the main water supply
   Shut off the water going into the filter system to prevent leaks or spills during the replacement.
2. Relieve pressure in the system
   Open a nearby faucet (usually downstream from the filter) to release any built-up pressure in the line.
3. Unscrew the filter housing
   Use the provided filter wrench to loosen and remove the housing. Have a bucket or towel ready to catch any residual water.
4. Remove the old filter
   Take out the used filter cartridge and discard it. Inspect the housing for sediment or debris.
5. Clean the filter housing
   Rinse the inside of the housing with clean water. If needed, use a mild soap and non-abrasive sponge to remove buildup. Rinse thoroughly.
6. Check and lubricate the O-ring
   Inspect the O-ring for wear or damage. If it’s in good condition, apply a small amount of food-grade silicone lubricant to help maintain a tight seal.
7. Install the new filter cartridge
   Place the new filter into the housing, ensuring it is properly seated and centered.
8. Reattach the housing
   Screw the housing back onto the system by hand, then tighten snugly using the filter wrench—do not overtighten.
9. Turn the water supply back on
   Slowly turn the main water supply back on while checking for leaks around the housing.
10. Flush the system (if required)
    Open a faucet downstream and let the water run for a few minutes to flush any carbon fines or air from the system.

How to Change Your Undersink Water Filter (Point-of-Use System)

Undersink water filters—also known as point-of-use (POU) systems—are installed beneath your kitchen sink to provide clean, great-tasting water from a dedicated tap. To ensure continued filtration performance, most filters should be replaced every 6 to 12 months, depending on usage and water quality.

Step-by-Step: Changing Your Undersink Water Filter

1. Turn off the cold water supply
   Locate the cold water shut-off valve under the sink and turn it off to stop water flow to the system.
2. Relieve pressure in the system
   Open the filtered water faucet to release any built-up pressure and drain any remaining water.
3. Disconnect the filter housing or cartridge
   Depending on your system, you’ll either:
   • Unscrew a canister-style housing using a filter wrench, or
   • Twist or release a quick-connect cartridge from the mounting bracket.
4. Remove the old filter
   Discard the used filter cartridge. Check for any sediment or buildup inside the housing if applicable.
5. Clean the housing (if applicable)
   Rinse the inside of the housing with clean water. Use mild soap and a soft cloth if needed. Be sure to rinse thoroughly to avoid any soapy residue.
6. Install the new filter
   Insert the new cartridge, ensuring correct orientation (follow any flow arrows or markings). For quick-connect styles, push or twist the new filter into place until secure.
7. Reconnect and tighten components
   Screw the housing back on or lock the new filter into position. Be careful not to overtighten threaded housings.
8. Turn the water supply back on
   Slowly reopen the cold water valve. Check for leaks at all connection points.
9. Flush the new filter
   Run water through the filtered faucet for 3–5 minutes to flush out air and any loose carbon particles.