Change the sediment cartridge every 6 to 12 months and the carbon cartridge about every 12 months, or sooner if pressure drops or chlorine taste returns. UV lamps need replacing yearly. A used sediment cartridge turns brown; that's normal and shows what the filter caught.
- Sediment: 6–12 months. Carbon: about 12 months. UV lamp: 12 months.
- Falling pressure or returning chlorine smell means a change is due.
- Keep a record of change dates.
Change schedule
| Part | Typical interval | Signs it's due |
|---|---|---|
| Sediment | 6–12 months | Pressure drop, brown and caked cartridge |
| Carbon block | ~12 months | Chlorine taste or smell returns |
| UV lamp | 12 months | Lamp still glows but output fades |
| Scale control media | 3–5 years | Scale reappears on fixtures |
Why does the cartridge turn brown?
It's trapped rust, silt and grit from the mains and your pipes. The colour varies by street and season, and it's the clearest proof the filter is working. At each Care Plan visit we photograph your old cartridge and send you the photo.
DIY or Care Plan?
Cartridge swaps on an installed system are straightforward once the bypass is set up, but the water must be isolated correctly and new carbon flushed. The Care Plan covers cartridges, the visit and a yearly re-test. The first 12 months are included, then a low monthly fee, confirmed in your quote.
Questions
What happens if I don't change my whole house filter?
Pressure drops as the sediment cartridge clogs, and the carbon stops reducing chlorine once it's exhausted.
How much do replacement cartridges cost?
It depends on cartridge size and how much water you use, so ask for the yearly figure in writing. With Whole Home Water, cartridges and changes are covered by the Care Plan: the first 12 months are included, then a low monthly fee, confirmed in your quote.
- Standards Australia: AS 3497:2021 drinking water treatment units
- NSF: drinking water treatment standards
Written by the Whole Home Water team and reviewed against the Australian Drinking Water Guidelines. General information only; your Home Water Check gives advice for your home.
Plumbing and installation details reviewed by a licensed plumber. See our editorial policy.