No Hot Water? What to Check, What It Costs to Fix and When to Replace
Most "dead" hot water systems are one of a few things: a tripped switch, an off-peak tank that has run out, a pilot that has gone out, or one failed part. Here are the checks the manufacturers say you can do yourself, what a repair costs if it's more than that, and how to tell when it's time to replace.
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Don't relight or reset anything, don't use electrical switches, put out any flames and get everyone outside. If it's safe, turn the gas off at the meter (or the cylinder for LPG). Then call your gas distributor's emergency line from outside, or 000 if anyone is in danger.
Gas emergency numbers by area
- Victoria: Multinet Gas (inner and outer east Melbourne, Yarra Ranges, South Gippsland), 132 691
- Victoria: Australian Gas Networks (north and south-east Melbourne, northern and eastern Victoria), 1800 427 532
- Victoria: AusNet Services (central and western Victoria), 13 67 07
- New South Wales: Jemena (Sydney and most of New South Wales), 131 909
- New South Wales: Australian Gas Networks (parts of regional New South Wales), 1800 427 532
- ACT: Evoenergy, 13 19 09
- South Australia: Australian Gas Networks, 1800 427 532
- Western Australia: ATCO Gas Australia, 13 13 52
- Tasmania: Tas Gas Networks, 1802 111
- Queensland, Northern Territory and LPG: use the emergency number on your gas bill, or on the cylinder or tank.
Numbers from the distributors' own pages and Energy Safe Victoria: gas emergencies, checked 13 October 2026.
Safe Checks by System Type
Electric storage
- Check the switch, fuse or circuit breaker marked HOT WATER at the switchboard is on, and the isolating switch near the heater if there is one.
- If you are on an off-peak tariff, the tank only heats in set hours. A big day of use can empty it until the next heating period.
- Run the hot tap for longer: cold water sitting in the pipes delays hot water at the tap.
Leave to a licensed trade: Elements, thermostats and anything behind the front cover are live 240V parts: call a licensed electrician or plumber.
Gas storage
- Check the gas valve on the heater supply line is open, and test another gas appliance such as the cooktop.
- If the pilot is out, relight it only by following the instructions printed on the heater. Rinnai's guide says turn the control to OFF and wait 5 minutes before trying, and never light it if you smell gas.
Leave to a licensed trade: A pilot that won't stay lit, or any thermocouple, gas valve, burner or flue problem, needs a licensed gasfitter. Rinnai says its heaters have no user-serviceable parts.
Gas continuous flow
- Check the unit is powered (test its power point with another appliance) and the gas and water valves are fully open. On LPG, check the bottle.
- Read the error code on the controller and look it up in the owner guide. On Rinnai units, 11 means no ignition or no gas, and 12 means the flame went out. Many codes clear by turning the hot tap off and on, then the unit off and on.
- Open the hot tap fully: a very low flow can stop the burner firing.
Leave to a licensed trade: Any other code, or an igniter, circuit board or gas valve fault, is a licensed gasfitter job.
Heat pump
- Check the HOT WATER switch at the switchboard is on. After power comes back the compressor waits a couple of minutes before starting, and reheating a tank can take several hours.
- In very cold or very hot weather some heat pumps, such as Rinnai's Enviroflo, hand over to a backup element, which is slower. Ice on the unit is cleared by a built-in defrost cycle. That is normal, not a fault.
- Look up any flashing light or fault code in the owner guide.
Leave to a licensed trade: Refrigeration and compressor faults, and draining the unit, are for a licensed technician or the maker.
Solar
- Check the booster switch at the switchboard and any booster timer. In cloudy weather and winter the booster does more of the work.
- Check the solar controller's power outlet is on.
Leave to a licensed trade: Booster element and thermostat faults, and air in the collectors, are for a licensed plumber or the dealer.
Summarised from the makers' owner guides: Rheem troubleshooting guide, Rinnai 4 Star gas storage owner guide, Rinnai Infinity continuous flow owner guide, Rinnai Enviroflo heat pump owner guide, Solahart owner guide (September 2025) and Dux hot water troubleshooting guide. Your model's own guide comes first.
Anything inside the unit, any gas part and any wiring is a job for a licensed plumber, gasfitter or electrician. In New South Wales all plumbing and gasfitting work needs a licence (NSW Government: plumbing, draining and gasfitting work), and in Victoria unqualified electrical work is illegal (Energy Safe Victoria: electrical work you must not do yourself).
What a Hot Water Repair Costs
| Repair | Typical cost |
|---|---|
| Call-out and diagnosis Capital Plumbing $80 to $150; The Quote Yard $100 to $180 in Melbourne | $80 - $180 |
| Electric element The Quote Yard $250 to $500 ($280 to $550 in Melbourne); Capital Plumbing $200 to $450 | $200 - $550 |
| Thermostat (electric) The Quote Yard $200 to $400; Capital Plumbing $150 to $350 | $150 - $400 |
| Thermocouple or ignition (gas storage) The Quote Yard $150 to $350; Capital Plumbing $200 to $500 or more | $150 - $500 |
| Gas control valve $400 to $800 in Melbourne | $200 - $800 |
| Relief valve (TPR) | $150 - $300 |
| Anode What's The Damage $200 to $500 nationally, $210 to $525 in Melbourne; The Quote Yard from $150 | $150 - $525 |
| Minor leak at a fitting | $150 - $400 |
| Continuous flow circuit board $300 to $600 for the part plus $150 to $250 labour | $450 - $850 |
| Heat pump component | $300 - $1,000 |
Published 2026 ranges from The Quote Yard, hot water system repairs Victoria 2026 (published 24 Aug 2026), Capital Plumbing, hot water system repair cost (21 Jul 2026) and What's The Damage, hot water system cost (October 2026). Indicative only: your plumber's quote decides.
Water around the unit is a different problem. See hot water system leaking: what to do.
Repair or Replace?
Repair a younger system with a single failed part. Replace it if the tank itself is leaking, the system is past about three quarters of its expected life, or the repair would cost more than half a new unit. (rule of thumb from The Quote Yard, hot water system repairs Victoria 2026 (published 24 Aug 2026).)
| System | Typical life |
|---|---|
| Electric storage | 8 to 15 years |
| Gas storage | 8 to 12 years |
| Heat pump | 10 to 15 years |
| Gas continuous flow | 15 to 20 years (Canstar says more than 20) |
From The Quote Yard, hot water system repairs Victoria 2026 (published 24 Aug 2026), Capital Plumbing, hot water system repair cost (21 Jul 2026) and Canstar: hot water systems. Solar Victoria: choosing a hot water system puts the typical life of a hot water system at 8 to 10 years. The manufacture date is on the compliance plate on the side of the unit.
Replacing anyway? See what a hot water system replacement costs, or compare Rheem, Rinnai, Thermann and Dux prices.
Gas hot water in Victoria? From 1 March 2027, Victorian law requires a mains gas hot water unit that fails in an existing home to be replaced with an electric one. Limited exemptions apply, for example where there is no room for an electric unit. What replacing gas hot water in Victoria costs.
Frequently Asked Questions
Why do I suddenly have no hot water?
The most common causes are a tripped hot water circuit or switch at the switchboard, an off-peak tank that has run out until its next heating period, a gas pilot that has gone out, a continuous flow unit showing an error code, or a failed part such as an element, thermostat or thermocouple. Start with the safe checks for your system type above.
How much does it cost to fix a hot water system?
Most single-part repairs cost $150 to $550 including labour in 2026 cost guides, plus a call-out of about $80 to $180. A gas control valve or a continuous flow circuit board can run to $800 or more. A leaking tank cannot be repaired and means replacement.
How long does it take for hot water to come back?
An electric tank on off-peak only heats in set hours. A heat pump waits a couple of minutes after power returns and can take several hours to reheat a full tank. A gas storage tank recovers faster, and a continuous flow unit heats on demand once it is working.
Should I repair or replace an old hot water system?
A rule of thumb from 2026 repair guides: repair a younger system with one failed part; replace it if the tank leaks, it is past about three quarters of its expected life, or the repair would cost more than half a new unit. Most storage systems last 8 to 15 years.
Can I replace a broken gas hot water system with gas in Victoria?
Until 28 February 2027, yes. From 1 March 2027, Victorian law requires a mains gas hot water unit that fails in an existing home to be replaced with an electric one. Limited exemptions apply, for example where there is no room for an electric unit. Repairs to an existing gas unit are still allowed.
What are you replacing?
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