Worked Estimates and Checklists
Switchboard upgrades and new circuits for air conditioners and heat pumps: the hidden electrical costs
When a split system, ducted unit or heat pump water heater needs a new circuit or switchboard upgrade in Australia, what drives the cost and how to spot it before installation day.
Many heating, cooling and hot water quotes in Australia leave out, or price separately, the electrical work: a dedicated circuit from the switchboard, an outdoor isolator, extra safety switches (RCDs) and sometimes a full switchboard upgrade in older homes. On this site's illustrative ranges, a straightforward new circuit might add a few hundred dollars, while a switchboard replacement in an older house with ceramic fuses can add a couple of thousand or more. The amount depends on the switchboard's condition, the distance to the unit, the network's supply capacity and your state's wiring rules. Ask for this to be assessed at the inspection, not discovered on installation day. This guide is part of the heating and cooling quote checklist.
All prices are illustrative, not quotes.
Why new appliances can need electrical work
| Appliance | Typical electrical needs |
|---|---|
| Small wall split (around 2.5–3.5 kW) | May connect to an existing circuit in some cases, but many installers prefer a dedicated circuit; outdoor isolator |
| Larger split (around 7 kW and up) | Usually a dedicated circuit; outdoor isolator |
| Ducted reverse cycle | Dedicated circuit, often larger cable; isolators at indoor and outdoor units; some larger units need three-phase supply |
| Heat pump water heater | Dedicated circuit; may connect to a controlled-load circuit if the meter and tariff allow |
| Replacing gas appliances entirely | Several new circuits; total household load rises |
The electrician decides what is required under the Australian wiring rules (AS/NZS 3000) and your state's electrical safety regulations. Whether an existing circuit can be used depends on its rating, the cable and what else is on it.
Signs your switchboard may need an upgrade
- Ceramic rewireable fuses instead of circuit breakers.
- No safety switches (RCDs), or only one covering some circuits.
- No spare space for new breakers.
- Signs of heat, burning smells or a board that trips often.
- Old switchboards with backing panels that may contain asbestos in older homes (pre-1990), which must be handled appropriately.
If any of these apply, budget for an upgrade and ask the installer to have their electrician inspect the board before quoting.
Illustrative cost ranges
| Electrical item | Illustrative range (incl. GST) | Notes |
|---|---|---|
| Dedicated circuit, short run, space on board | $250–$600 | Depends on distance and access |
| Dedicated circuit, long run or two-storey | $500–$1,000 | Roof or wall access time |
| Outdoor isolator | Usually included in circuit price | Required for outdoor units |
| Additional RCBO or RCD | $100–$300 per device | Depends on board |
| Switchboard upgrade (replace fuses with breakers and RCDs) | $1,200–$3,000 | More if asbestos backing or meter panel work |
| Consumer mains or supply upgrade | Varies widely | May need network approval; sometimes the network's own charges apply |
These are site assumptions to show the method. Get the electrical scope written on the quote.
Worked example: adding two splits and a heat pump
Illustrative example. A 1970s house with ceramic fuses and no spare space is adding a 7.1 kW living-room split, a 2.5 kW bedroom split and a heat pump water heater replacing gas.
| Item | Illustrative cost |
|---|---|
| Switchboard upgrade to breakers and RCDs | $1,800 |
| Three new dedicated circuits (two splits, one heat pump) | 3 × $400 = $1,200 |
| Electrical total | $3,000 |
Compare with the equipment and installation costs: 7.1 kW split ($3,185–$4,960), 2.5 kW split (about $2,200–$2,950) and heat pump ($3,800–$5,600 replacing gas). With equipment and installation at about $9,200–$13,500, the gross job is about $12,200–$16,500, so electrical work is roughly a fifth to a quarter of it in this illustration — easily the difference between two quotes. Use the installation cost estimator and include the electrical line in the fixed cost.
Controlled load and tariffs
A heat pump water heater can often run on a controlled-load circuit (where available), which usually has a cheaper tariff but supplies power only at certain times. Things to check:
- Does your meter and tariff include controlled load?
- Will the heat pump's operating window give enough hot water for your household?
- Would a timer on a general circuit during solar hours be cheaper if you have rooftop solar?
Changing tariff arrangements can involve your retailer, a metering coordinator and sometimes the network. See the running-cost guide.
Three-phase power and larger ducted systems
Some larger ducted systems are available in single-phase and three-phase versions. If your home is single-phase, choose a single-phase model unless you plan a supply upgrade, which can be costly and requires the network's involvement. Ask the installer which supply the quoted model needs.
Paperwork to expect
After any electrical work, the electrician must give you the compliance document required in your state. Names differ: for example a Certificate of Electrical Safety in Victoria and a Certificate of Compliance for Electrical Work in NSW. Keep it with your warranty and incentive paperwork. It may be needed for warranty claims and for incentive programs that require proof of compliant installation.
How to avoid electrical surprises
- Ask for a photo of your switchboard to be reviewed at the quoting stage, or for the electrician to attend the inspection.
- Ask whether the quote assumes spare capacity and an existing circuit.
- Ask for electrical items as separate lines with prices.
- Check the electrician's licence with your state regulator.
For more problems that show up after installation, see common installation mistakes.
Frequently asked questions
Can a split system plug into a power point?
Small portable or plug-in units exist, but fixed split systems are generally hard-wired or connected to a dedicated outlet installed by a licensed electrician. Follow the manufacturer's instructions and your electrician's advice.
Who pays for a supply upgrade from the street?
Usually the property owner pays the electrician, and the network may charge separately for its work. Ask your retailer and network before committing.
Is an RCD required for a new air conditioning circuit?
Current wiring rules generally require RCD protection for new final subcircuits in homes. Your electrician will confirm what applies.
Will the installer's electrician do the switchboard?
Sometimes. Some installers subcontract electrical work; others leave the board to you. Get it in writing.
Official sources
- Energy Safe Victoria — electrical safety and certificates in Victoria
- NSW Fair Trading — electrical licensing and compliance certificates in NSW
- energy.gov.au — tariffs and household energy information
- Energy Made Easy — compare tariffs, including controlled load
