How to install a kitchen mixer tap

🔧 How to install a kitchen mixer tap — Australian trade guide

What is involved in installing a kitchen mixer tap in Australia?

Installing a kitchen mixer tap is a common upgrade that can improve usability, appearance and water efficiency in your kitchen. In Australia, most mixer tap replacements are straightforward where the new tap suits the existing sink or benchtop hole, the existing isolation valves work properly, and no pipework alterations are required.

Plumbing work in Australia must be performed by a licensed plumber. This guide explains the process and helps you select the right tools and materials. For compliance, installation should align with the Plumbing Code of Australia (PCA) and AS/NZS 3500 requirements for water services, fixture connection and leak-free commissioning.

What skill level is required to install a kitchen mixer tap?

Beginner to Intermediate — Estimated time: 1 to 2 hours

What tools are essential for kitchen mixer tap installation?

What materials are needed for a kitchen mixer tap replacement?

🪵 Materials

Safety Requirements

Step-by-Step Guide

Step 1: 1️⃣ Confirm the tap suits your sink and existing connections

Check whether your new mixer is designed for a single tap hole installation and confirm the required hole size, usually around 32 mm to 35 mm. Measure the sink or benchtop thickness and make sure the mixer’s fixing kit is suitable.

Also confirm the spout reach and height. In kitchens with overhead cupboards, a very tall gooseneck mixer can foul on cabinetry. If the sink is close to a window, check whether the handle or spout can operate fully.

💡 Choose a mixer with a good WELS rating. A 4-star or better unit is a practical balance of flow and water efficiency for most homes.

Step 2: 2️⃣ Clear the cabinet and isolate the water

Remove all stored items from under the sink so you have full access to the pipework and tap mounting area. Place a bucket and rags below the isolation valves and flexible hose connections.

Turn off the hot and cold isolation valves under the sink, usually 15 mm mini stop taps, by rotating them clockwise. Open the existing kitchen tap to relieve pressure and drain residual water from the lines.

If the isolation valves do not fully shut off, or the handles are seized, stop here and call a licensed plumber. Replacing faulty isolation valves is not the same as a simple tap swap.

Step 3: 3️⃣ Disconnect the old mixer tap

Use a shifter or multigrips to loosen the hot and cold flexible hose connections from the isolation valves. Expect a small amount of water to drain into the bucket.

Next, locate the tap retaining nut, horseshoe clamp or fixing plate underneath the sink or benchtop. These are often difficult to reach, so a basin spanner or tap backnut tool helps. Remove the fixing hardware and lift the old mixer out from above.

If old silicone or grime is holding the base in place, carefully cut around it with a utility knife and clean the mounting surface thoroughly.

Step 4: 4️⃣ Inspect the valves, hoses and mounting surface

Before installing the new tap, inspect the isolation valves for corrosion, leaks or thread damage. Check that the hot and cold outlets are secure and aligned.

Look at the sink or benchtop tap hole for rust, swelling, cracks or movement. A loose or distorted mounting surface can prevent the new mixer from sealing properly and may lead to leaks beneath the sink.

If the old tap leaked through the base, clean away scale and residue so the new sealing ring can sit flat.

Step 5: 5️⃣ Pre-assemble the new mixer tap

Follow the manufacturer’s instructions exactly. Most kitchen mixers come with pre-attached or separate braided flexible hoses, a rubber or foam sealing ring, threaded mounting stud and retaining bracket.

Fit the sealing ring or gasket to the mixer base as directed. If the manufacturer specifies a stabilising plate for thin stainless sinks, install it. This helps prevent tap wobble over time.

Do not apply thread tape to braided flexi hose unions that seal with a rubber washer unless the manufacturer specifically instructs it. These fittings usually seal on the washer, not on the thread.

Step 6: 6️⃣ Feed the hoses through the sink hole and position the mixer

Pass the hot and cold hoses through the sink or benchtop hole first, then lower the mixer body into place. Align the mixer so the handle faces the correct direction and the spout is centred over the bowl.

From below, fit the mounting bracket, horseshoe plate or retaining washer and start the nut by hand. Before fully tightening, return above the sink and make final alignment adjustments.

Once aligned, tighten the retaining nut firmly but do not overtighten. The mixer should sit solidly without twisting, but excessive force can deform thin sinks or damage the fixing kit.

Step 7: 7️⃣ Connect the hot and cold water supplies

Connect the flexible braided hoses to the appropriate isolation valves. In most Australian installations, hot is on the left and cold is on the right when facing the tap.

Thread the nuts on by hand first to avoid cross-threading. Tighten with a shifter only enough to compress the sealing washer correctly. Avoid twisting or kinking the hoses; they should form smooth bends with no strain.

If the hose tails are too short, do not improvise with unsuitable joiners. Use only compliant fittings and manufacturer-approved connection methods, or have a licensed plumber alter the pipework.

Step 8: 8️⃣ Slowly restore the water and flush the tap

With the tap handle in the off position, slowly reopen the isolation valves. Check underneath immediately for drips at the hose unions and around the tap body.

Remove the aerator if the manufacturer recommends flushing before final use. Then turn on the mixer and run both hot and cold water for 1 to 2 minutes to clear debris, air and installation residue from the lines.

Reinstall the aerator and test all handle positions, including full hot, full cold and mixed flow. Confirm smooth operation and correct water temperature response.

Step 9: 9️⃣ Leak test, final tighten and clean up

Dry all fittings with a clean rag, then watch for any fresh moisture forming over the next few minutes. Check:

If a hose connection drips, gently tighten it a little more. If leaking continues, turn the water off and inspect the washer or seating surface.

Wipe down the tap, replace cabinet contents and keep an eye on the installation over the next 24 hours for slow seepage.

Common Mistakes to Avoid

Pro Tips

Recommended Tools