How to Turn Off Your Water Mains Before Installing a Water Filter

Before any whole house water filter installation, one of the first practical steps is knowing how to safely shut off your water mains. It sounds simple, but getting it wrong can mean a rushed, messy job.

Find Your Main Shut-Off Valve

Most Australian homes have a stop tap near the water meter, usually at the front boundary of the property, plus sometimes a secondary internal isolation valve closer to the house. It is worth locating both before you start any work, not during an emergency.

Turning It Off Safely

Mains valves are typically turned clockwise to close, but they can be stiff if they have not been used in years. Turn gently and avoid forcing an old valve, since a worn tap washer can crack under pressure.

Releasing Residual Pressure

After the mains is off, open a tap at the lowest point of the house to drain remaining pressure and water from the pipes before disconnecting anything, which reduces mess and makes fittings easier to work with.

When to Call a Professional

If your stop tap is seized, hard to access, or you are not confident identifying it, this is a reasonable point to bring in a licensed plumber rather than risk a flood or a damaged valve.

Installation Considerations: How to Turn Off Your Water Mains Before Installing a Water Filter

Getting how to turn off your water mains before installing a water filter right starts before any tools come out — with confirming your incoming water pressure, the location of your water meter and mains isolation valve, and whether your plumbing configuration (copper, PEX, or poly) suits a push-fit or compression connection. In Victoria, any permanent alteration to household plumbing, including whole house filtration installed after the meter, must be carried out or signed off by a licensed plumber to comply with local regulations and to keep your home insurance and warranty valid.

All fittings and housings we supply and install are WaterMark certified, meaning they’ve been independently tested and approved for use in Australian plumbing systems under the Plumbing Code of Australia. This isn’t just a compliance checkbox — WaterMark certification is your assurance that a fitting won’t fail under normal household pressure and won’t contaminate your water supply.

Verified Standards & Further Reading

For homeowners who want to verify the certification claims made in this article, we encourage you to check the primary sources directly rather than taking any supplier’s word for it (including ours):

• Search any plumbing product’s WaterMark certification status directly on the Australian Building Codes Board’s official WaterMark product database.
• Verify NSF/ANSI certified water treatment products and the specific standard they are tested against via the official NSF certified product listings.
• Read the current Australian Drinking Water Guidelines published by the National Health and Medical Research Council for the official national standards on drinking water quality.

All AquaCo filtration systems supplied and installed by Vic Water Filters carry WaterMark Licence No. 23448 and are independently tested to the relevant NSF/ANSI standards for their stated contaminant reduction claims, including PFAS/PFOA and PFOS reduction where specified on the individual product datasheet.