Before the install: the site visit
Most quality installers do a free site visit (or detailed video call) before quoting on anything except the simplest back-to-back split. They'll measure room dimensions, check ceiling cavity, find a route for copper pipes, identify the best outdoor unit position, check your switchboard capacity, and look at potential issues (asbestos, weatherboard cladding, structural beams in roof cavity). If an installer quotes sight-unseen on a complex job, expect scope-creep on install day.
Split system install — step by step
1) Drop sheets and dust protection. 2) Mark the indoor head position (usually 200–300mm below the ceiling, away from doorways). 3) Drill the wall penetration (60–75mm core hole) with proper dust extraction. 4) Mount the indoor head's wall bracket and the outdoor unit's wall/ground mount. 5) Run copper pipe (liquid + gas line, insulated), electrical cable and condensate drain through the wall. 6) Connect pipework with flare nuts, torqued to spec. 7) Vacuum the pipework (proper deep vacuum to remove moisture and air — 30+ minutes minimum). 8) Open the refrigerant valves and check for leaks. 9) Power on, commission, test heating and cooling, check temperature differential at the indoor head (8–12°C drop is typical). 10) Walk through with you, show how to use the remote, clean up, hand over warranty paperwork.
Red flags during a split install
Skipping the vacuum step (some installers cheat with a 5-minute purge — this leaves moisture in the system and shortens life dramatically). Not using a torque wrench on flare connections. No drop sheets or dust extraction. Mounting the outdoor unit on a flimsy bracket. Refusing to commission and walk through with you. Less than 30 minutes total on basic commissioning.
Ducted install — step by step
Day 1: protect the home, access roof cavity, install brackets for the indoor air handler, lay insulated flexi-ductwork to each room, cut ceiling vent positions. Day 2: install the outdoor unit on a stable base or roof mount, run insulated copper pipe between indoor and outdoor units, wire control cables to each zone, install the wall controller. Day 3: pressure-test and vacuum the system, gas-charge, commission, balance airflow at each vent, walk through controller use and zone setup.
What good commissioning looks like
On cooling, supply air should be 8–12°C below the return air. On heating, supply air should be 18–25°C above. Static pressure (for ducted) should match the air handler's design spec. Refrigerant charge should be verified by superheat and subcool measurements, not by the gauge needle alone. A proper install report documents all these numbers.
Cleanup and handover
All packaging removed. Old unit disposed of (if applicable). Any drilled debris vacuumed and cleared. Wall and ceiling penetrations sealed with proper fire-rated sealant where required. Owner's manual, remote, Wi-Fi pairing instructions, warranty registration handed over. Installer should walk you through using the system and explain maintenance basics.
Post-install: when problems show up
Most install problems become visible in week 1: water dripping from indoor head (drain not pitched correctly), insufficient cooling (low refrigerant charge or wrong sizing), tripping breakers (electrical wrong), noisy outdoor unit (poor mounting). Report any of these to the installer immediately — they're covered by your workmanship warranty.