Replacing hot water in Perth
Staying on gas
ATCO Gas Australia owns the gas networks across greater Perth, including Mandurah. A gas-to-gas swap needs a licensed gas fitter for the gas connection as well as the plumbing.
Cool nights, not cold ones
The mean July minimum is 8.1°C at both Perth Airport and Perth Metro. If you're weighing a heat pump, that is the kind of winter morning it will work through.
Hardness inside the guideline
Water Corporation says the metro supply meets the national hardness guideline. It still recommends letting the pressure valves on a hot water system release for a few seconds every month.
A tempering valve on the swap
WA requires a temperature control device whenever a water heater is replaced or relocated. Basins are the only exception, so budget for it in a like-for-like job too.
Planning a replacement
Read the label on the old unit
Brand, size, fuel and age. Gas or electric, storage or continuous flow, it decides which trades need to come.
Decide: same again, or a switch
Heat pumps and solar can create STCs, which lower the price. Leaving gas means a gas fitter has to deal with the old gas line.
Get a quote that shows the licence number
WA requires a plumbing contractor's licence or permit number on quotes and invoices. No number, no booking.
Expect a notice before work starts
The contractor lodges a notice of intention at least 24 hours ahead. Ask them to confirm it's been lodged.
Keep the certificate
A certificate of compliance is due within five working days of finishing. File it with any Notice of Completion from the gas fitter.
What each change involves in WA
| Who works on it | Paperwork you should end up with | |
|---|---|---|
| Gas to gas | A licensed plumber, plus a licensed gas fitter for the gas side | Certificate of compliance, and a Notice of Completion within 48 hours of the gas work |
| Electric to electric | A licensed plumber; a restricted permit holder only if no pipes change | Certificate of compliance |
| Gas to heat pump or solar | A licensed plumber for the water side, and a gas fitter for the old gas line | Certificate of compliance, a Notice of Completion, and STC paperwork if you assign the certificates |
Discounts, and what we couldn't find
There's no WA hot water rebate in our research. The discount that does apply is national: assign the STCs on an eligible heat pump (under 425 L) or solar water heater (under 700 L) to an agent, and the price drops or you're paid later. The model must be on the register, and the installer must meet WA's licensing rules.
We also haven't found a WA rule like Victoria's 2027 gas hot water rule, so a gas replacement is still your choice. Compare the options on our hot water comparison before the day you need hot water back.
Questions before you say yes
- Does the quote include the tempering valve WA requires on a replacement?
- Who lodges the notice of intention, and who sends me the certificate?
- Will the old gas line be capped, and by whom?
- Is the STC discount already in this figure, and which agent gets the certificates?
- Will you take the old unit away?
What we would do
Treat a leaking tank as notice, not as the deadline. Use the days it still works to decide between gas, heat pump and solar, and ask for one written quote that lists the tempering valve, the gas work and any STC discount. When the job is done, check you have the certificate of compliance within five working days, and the Notice of Completion if gas was involved. A licence-checked plumber who specialises in hot water replacement will expect you to ask for both.