You have decided on a new aircon. You have measured the rooms, picked the brand, even chosen the controller. Then the installer turns up, pops the switchboard cover, and tells you the upgrade you booked cannot go ahead until the switchboard is brought up to current standards.
This is one of the most common reasons aircon installs get delayed in Australia — and one of the most overlooked when people compare quotes.
Why your aircon needs more than just an installer
Modern reverse cycle aircon — particularly ducted units and high-capacity multi-head splits — draws significantly more power than the heating systems of even ten years ago. A 14kW ducted unit can pull 25 amps or more on startup. If your home was built before the early 2000s, your switchboard was probably never designed for that kind of load.
Three things commonly come up:
- No safety switches (RCDs): Older switchboards often have circuit breakers but no residual current devices. Australian standards require RCD protection on new circuits, including the dedicated aircon circuit.
- Insufficient amperage on the main supply: Some older homes still run on 60 or 80 amp single-phase service. A modern aircon plus existing kitchen appliances and EV charging tips this over the limit.
- Old ceramic fuse boards: If you have ceramic fuses, you almost certainly need a switchboard upgrade before any new aircon circuit goes in.
What a typical aircon-driven switchboard upgrade looks like
A switchboard upgrade is not a small job, but it is also not the catastrophe people sometimes fear. A good electrician can usually have it done in a single day. Here is what is typically involved:
- Replace the old switchboard enclosure
- Install RCD safety switches on all circuits
- Install a dedicated aircon circuit sized to the unit
- Test all circuits and label them properly
- Issue the certificate of electrical safety
Costs in Australia in 2026 typically range from around $2,500 for a straightforward residential upgrade up to $5,500+ for larger homes or where the main supply also needs to be increased. Three-phase upgrades sit higher again.
How to check if your switchboard will be a problem before you book the aircon
The simplest pre-check: open your switchboard and look for these signs that an upgrade is likely needed before any aircon install:
- Round ceramic fuses instead of breakers
- No RCDs (no buttons labelled “Test” on any of the switches)
- Switchboard looks crowded with no spare circuit slots
- Last upgrade was over 20 years ago
- The main switch is rated below 80 amps
If two or more of those describe your switchboard, expect the aircon installer to flag it. Better to know that before you sign the install contract.
Why this catches people out on quotes
Aircon installers quote based on the install itself. They typically do not include switchboard upgrades in the headline price because the upgrade may or may not be needed. When the install day arrives and the upgrade IS needed, you suddenly have a $2,500-$5,000 add-on you were not budgeting for.
The fix: get your switchboard checked before you book the aircon. Some installers will do this as part of their site visit. Otherwise, ask a licensed electrician to inspect it and tell you what work is needed for the aircon load you are planning.
Melbourne electricians like Electrx see this all the time. Their team often gets called in after an aircon installer has flagged the switchboard issue mid-job — and a switchboard upgrade booked properly in advance is faster, cheaper, and means the aircon install runs to schedule.
The order of operations that saves money
If you are planning an aircon install in 2026, the smart sequence is:
- Get your switchboard inspected by a licensed electrician
- If an upgrade is needed, get that done first as a separate booking
- Then book the aircon install knowing the switchboard is ready
It looks like more steps but it is faster overall. Aircon installers love going into a job where the electrical work is already sorted — they get in, install the unit, and you get cool air without the surprise invoice.
Skipping this check is one of the most common reasons aircon installs blow out in cost and timeline. A 30-minute switchboard inspection can save weeks of delay and thousands of dollars.
