Short answer: A heat pump hot water system usually needs a suitable dedicated circuit, often wired to an off-peak or controlled-load tariff or set on a timer to use solar, plus a licensed plumber for the water connections. If you’re replacing an electric storage heater, the existing circuit may be reusable after checks. The NSW Government offers an upfront discount of up to $640 when replacing an electric water heater, or up to $330 when replacing gas, through accredited installers.
Hot water is one of the biggest energy users in most homes. Heat pumps work like a reverse air conditioner, pulling heat from the air to warm water, and use far less electricity than a traditional electric element. Here’s what the electrical side involves, especially in compact Inner West homes.
What the NSW discount covers
Under the NSW Energy Savings Scheme, the NSW Government hot water upgrade page says eligible households can get an upfront discount of:
- up to $640 when replacing an electric water heater with a heat pump
- up to $330 when replacing a gas water heater with a heat pump
The discount is applied by an accredited provider, and the amount varies with the product and location. Check the current eligibility rules before you buy, as programs change.
The electrical checklist
| Item | What to check |
|---|---|
| Circuit | Dedicated circuit sized for the heat pump’s rating, protected at the switchboard |
| Tariff | Whether it’ll be on a controlled-load (off-peak) circuit, normal tariff, or timed to solar |
| Switchboard | Spare space, safety switch protection, and room for controlled-load wiring |
| Isolator | Isolation near the unit, as required for the installation |
| Location | Outdoor position with airflow, close to the existing hot water if possible |
| Cable run | Path from the switchboard to the new location, especially if moving the unit |
Controlled load vs solar timing
Older electric storage heaters in many Inner West homes run on a controlled-load tariff, where the network switches the water heater on overnight at a cheaper rate. Heat pumps can work on controlled load too, but check the manufacturer’s advice, because some run better with longer heating windows.
If you have solar panels, many households set the heat pump to run in the middle of the day on a timer, using their own solar power. That can mean moving the heat pump to a normal-tariff circuit with a timer. Your electrician can explain the options for your meter and tariff. Note that changes to metering itself are network-side work for a Level 2 Accredited Service Provider or your retailer. Blue Link is not Level 2 accredited.
Replacing electric storage
This is often the simplest swap. The existing circuit may be reusable if it’s in good condition, protected by a safety switch and suited to the new unit’s rating. Your electrician will:
- isolate and disconnect the old heater
- check the cable, protection and safety switch
- connect the heat pump, adding an isolator if needed
- test and lodge a compliance certificate
Replacing gas
If you’re replacing gas hot water, there’s usually no existing circuit at the hot water location, so a new one is needed. Combine it with other electrification work, like induction cooking or a new switchboard, to save on labour and switchboard changes. A licensed gasfitter will disconnect the gas.
Placement in terraces and small blocks
Heat pumps need airflow and make a low hum, a bit like an air conditioner’s outdoor unit. On narrow Inner West blocks, think about:
- noise near bedroom windows, yours and your neighbours’
- side passages, where airflow can be limited
- access for future servicing
- council or strata rules, especially in apartments and heritage areas
Planning a heat pump? We handle the electrical side, including new circuits, isolators and switchboard work, and coordinate with your plumber. See our hot water systems service or call 0421 772 661.
Who does what
- Licensed plumber: water connections, tempering valve and installation of the unit
- Licensed electrician: circuit, isolation, switchboard and electrical connection
- Accredited provider: arranges the NSW discount if you’re claiming it
- Gasfitter: disconnects gas if replacing a gas system
Some plumbers hold an electrical licence or work with an electrician. Ask who is doing the electrical work and make sure you receive the Certificate of Compliance for Electrical Work, which NSW requires within 7 days of testing according to the NSW Government.
If your switchboard is old or full, read signs you need a switchboard upgrade first. We work in Hurlstone Park, Dulwich Hill, Marrickville and nearby suburbs.
Frequently asked questions
Does a heat pump hot water system need its own circuit?
Generally yes. It should be on a dedicated circuit sized to the unit’s rating, with appropriate protection and isolation.
Can a heat pump run on off-peak power?
Many can, but check the manufacturer’s advice. Some households prefer to run them during the day on solar power using a timer.
How much is the NSW heat pump discount?
The NSW Government lists an upfront discount of up to $640 when replacing an electric water heater and up to $330 when replacing gas, through accredited providers. Amounts vary, so check current eligibility.
Do I need an electrician and a plumber?
Usually yes. The plumber handles the water connections, and a licensed electrician does the electrical connection and any circuit or switchboard work.