How to Maintain a Whole House Water Filter: A Practical Guide

A whole house water filter is a set-and-forget system for most of the year — but it does need regular cartridge replacement and occasional checks to keep performing. Here’s what to do and when.

See our full Whole House Water Filters Guide or browse our replacement cartridge range.

Maintenance Schedule

How to Replace a Cartridge

1. Close the bypass valve to isolate the filter from the mains supply. If no bypass valve is fitted, shut off the mains water.
2. Release pressure by opening a tap downstream of the filter.
3. Unscrew the filter housing using the housing wrench (supplied with the system). Turn anticlockwise.
4. Remove the old cartridge and dispose of it. Rinse the housing with clean water.
5. Check the O-ring — clean it and apply a small amount of food-grade silicone grease if it looks dry or cracked. Replace if damaged.
6. Insert the new cartridge and hand-tighten the housing. Do not overtighten.
7. Restore water supply and check for leaks at the housing connection.
8. Flush for 2–3 minutes before use to clear any residual media from the new cartridge.

Pressure Drop: The Key Warning Sign

A noticeable drop in water pressure throughout the house is the most reliable sign that your sediment cartridge is clogged and needs replacing. Don’t wait for this — replace on schedule to avoid pressure problems. Browse our replacement cartridge range.

Frequently Asked Questions