How to Change a Water Filter or Purifier Cartridge: Step-by-Step

Changing your water filter cartridge is one of the most important maintenance tasks you can do — and it’s simpler than most people expect. Here’s a practical guide covering the most common filter types in Australian homes.

Browse our replacement cartridge range or see our related guide: How to Replace a Water Filter Cartridge.

When to Change Your Filter

Replace sooner if you notice reduced flow, returning chlorine taste or smell, or visible discolouration in the cartridge.

Changing Benchtop or Whole House Filter Cartridges

1. Turn off the water supply to the filter.
2. Press the pressure relief button (if present) to release pressure.
3. Use the filter housing wrench to unscrew the housing bowl (anticlockwise).
4. Remove the old cartridge and drain the housing.
5. Rinse the housing with warm water. Inspect and lubricate the O-ring with food-grade silicone grease.
6. Insert the new cartridge, aligning it over the standpipe at the base of the housing.
7. Screw the housing back on firmly (don’t overtighten).
8. Slowly turn the water supply back on and press the pressure relief button to purge air.
9. Check for leaks and flush 2–3 litres through before use.

For more detail, see our full guide: How to Replace a Water Filter Cartridge.

Changing Reverse Osmosis Filters

1. Turn off the feed water supply valve.
2. Close the storage tank ball valve (quarter turn clockwise).
3. Open the RO faucet to release system pressure.
4. Place a shallow tray under the filter housings to catch spilled water.
5. Unscrew the filter housings from the cap (use a housing wrench if needed).
6. Remove old cartridges. Inspect O-rings — replace if cracked or deformed. Lubricate with silicone grease.
7. Clean housings with warm soapy water and rinse thoroughly.
8. Insert new cartridges and reassemble housings hand-tight.
9. Turn the feed water supply back on and check for leaks.
10. Open the RO faucet — you should see a steady trickle within a few minutes.
11. Flush several litres through the system before opening the storage tank valve.
12. Open the storage tank valve and allow the tank to refill (2–4 hours).

Replacing the RO Membrane

The membrane is replaced less frequently (every 24 months) and requires disconnecting the membrane housing tubing. Push down on the locking ring at each tube fitting to release the tubing. Unscrew the membrane housing cap, remove the old membrane (needle-nose pliers may help if it’s been in place for years), clean the housing, and insert the new membrane with the O-ring end facing the cap. Reassemble and reconnect tubing, pushing each tube firmly into its fitting until it locks.

Browse our RO systems and replacement cartridges.

Frequently Asked Questions