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Australia
Hot water system replacement cost
Replacing a gas storage hot water system like-for-like typically costs $2,100 including GST, with most quotes from $1,650 to $2,750. A basic unit is about $1,950, and a premium model with a longer tank warranty is closer to $2,350. Electric storage is usually cheaper to install; continuous flow gas costs a little more, and more again if the pipework or power point has to change.
Most homeowners pay
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mid-range, typicalCost by region
| Location | Basic | Mid-range | Premium |
|---|---|---|---|
| Australian Capital Territory | $2,050 | $2,200 | $2,450 |
| Northern Territory | $2,000 | $2,150 | $2,400 |
| Western Australia | $2,000 | $2,150 | $2,400 |
| New South Wales | $1,950 | $2,100 | $2,350 |
| Queensland | $1,950 | $2,100 | $2,350 |
| Victoria | $1,950 | $2,100 | $2,350 |
| South Australia | $1,900 | $2,050 | $2,300 |
| Tasmania | $1,850 | $2,000 | $2,250 |
What's included
Mid-range
- Draining, disconnecting and removing the old hot water system
- A 135-170 litre gas storage unit suited to a household of 4
- Gas and water connections in the same position
- New tempering valve, isolation and non-return valves, and relief valve drain
- Commissioning, gas leak test and compliance certificate from the licensed plumber
- Taking the old unit away
What affects the cost
Type of system
Electric storage is usually the cheapest to buy and install but costs the most to run, unless you have an off-peak tariff. Gas storage costs more up front. Continuous flow gas heats water on demand and never runs out, and costs a bit more again.
Changing type
Swapping like-for-like is quickest. Going from storage to continuous flow often needs a bigger gas pipe and a new weatherproof power point, and moving from gas to electric can need a new circuit from the switchboard.
Size
Tank size or flow rate should match the household and the number of showers used at once. Oversized systems cost more to buy and, for storage units, more to keep hot.
Location and access
Most systems are outside against a wall and easy to reach. Units inside a cupboard, in a roof space or up stairs take more time, and some internal gas units need a flue.
Brand and warranty
Tank warranties range from short periods on budget models to longer cover on premium ones. Mains water quality matters: in hard water areas the tank or heat exchanger can wear faster.
Emergency call-outs
Most replacements happen after a failure. After-hours or same-day work often costs more than a planned replacement.
How to save
- Plan the replacement when the unit is getting old rather than waiting for it to fail and paying an urgent call-out.
- Stay with the same type and position unless the running cost savings are clear.
- Compare a heat pump system too: STCs are applied as a discount, which narrows the price gap.
- Get two or three quotes from licensed plumbers and check what valves and removal are included.
Grants, tax and rules
Licensed plumbers
Gas, plumbing and electrical work on hot water systems must be done by licensed tradespeople under state licensing, and you should receive a compliance certificate.
Heat pump alternative
Heat pump hot water systems are usually quoted after STCs, a federal discount that steps down each year until the scheme ends in 2030. Standard gas and electric storage units do not attract STCs.
GST
Quotes to households include 10% GST, and our figures include it.
Frequently asked questions
How much does it cost to replace a hot water system?
A gas storage system replaced like-for-like costs around $2,100 including GST, with most quotes between $1,650 and $2,750. Electric storage is usually cheaper and continuous flow gas slightly dearer.
Is continuous flow better than a gas storage tank?
It never runs out and has no tank to keep hot, so it suits families with back-to-back showers. It costs a bit more, and switching from storage may need gas pipe and power point upgrades.
How long does a hot water system last?
Storage tanks commonly last 8 to 12 years, depending on water quality and whether the anode is serviced. Continuous flow units often last longer.
How long does installation take?
A like-for-like swap usually takes two to four hours. Changing system type can take most of a day.
Should I switch to a heat pump instead?
It is worth pricing, especially if you are on electric storage now, because a heat pump uses much less electricity. See our heat pump hot water guide for prices after STCs.
How this estimate is calculated
Work hours: 7 · Labour: $843 · Materials: $1,071
Sources: ABS Employee Earnings and Hours, Australia; Regione Toscana, Prezzario dei Lavori 2026 (CC BY 4.0); ECB exchange rates; market check: Mid = gas storage like-for-like. homeimprovementaustralia.com.au (2026-04-10): electric 800-2,500, gas storage 1,200-3,000, continuous flow 1,500-3,000; hipages (2026-01-22): electric 1,000-2,000, gas 1,500-3,000. Incl. GST..
Last reviewed 26 September 2026 · How we calculate costs · Editorial policy