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How to replace a water filter

We'll replace the filter cartridge so your water stays clean and flows properly.

How-to · Home plumbing
10–20 min
What you'll need
  • Replacement filter cartridge (match the model number)
  • Filter wrench (for housing-style filters)
  • Towel or bucket

At a glance

  • Shut off the water supply to the filter—usually a valve on the filter housing or under the sink.
  • Release pressure by opening the faucet that the filter feeds.
  • For cartridge filters: unscrew the housing, remove the old cartridge, insert the new one, and reinstall.
  • For whole-house filters: bypass the filter, drain the housing, replace the cartridge, and restore flow.
  • Flush the new filter for 2–3 minutes to remove carbon fines before use.
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Steps

Goal: Replace the filter cartridge without leaks or damage.

  • Shut off the water supply to the filter. Open the faucet to release pressure.
  • Good: Pressure is released. Proceed to Open the housing.
  • Bad: Water still flows—check shutoff valve or main supply.

Open the housing

Goal: Remove the old cartridge.

  • Place a towel or bucket. Use the filter wrench to loosen the housing. Remove the old cartridge.
  • Good: Old cartridge is out. Proceed to Install the new cartridge.
  • Bad: Housing is stuck—use the wrench for extra grip; do not force.

Install the new cartridge

Goal: Seat the new cartridge and seal the housing.

  • Rinse the housing. Check the O-ring. Insert the new cartridge. Reinstall the housing.
  • Good: Housing is tight. Proceed to Turn on and flush.
  • Bad: O-ring is damaged—replace it before reinstalling.

Turn on and flush

Goal: Restore water and flush the new filter.

  • Turn the water supply back on. Run water for 2–3 minutes to flush carbon fines.
  • Good: Water runs clear. Proceed to Verification.
  • Bad: Leak at a connection—tighten the housing or check the O-ring.

When to get help

Call a plumber if:

  • The housing will not open or the filter head is damaged.
  • You have a whole-house filter and the bypass or main valve is stuck.
  • Water pressure is still low after replacing the filter (may be a different issue).

Verification

  • No leaks at the filter housing.
  • Water flows at normal pressure.
  • Water is clear after the 2–3 minute flush.

Reviewed by Blackbox Atlas

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