Six-fifteen on a school morning in Gregory Hills. Three kids, one bathroom, and the shower is running cold. No hot water is the sort of problem that goes from mildly annoying to full household crisis in about ninety seconds, and the first instinct is to grab the phone.
Hang on a minute. A fair few of the “hot water not working” calls I take could have been sorted at the switchboard or the gas meter before I’d left the house. If the shower is cold right now, we are a hot water plumber, no call-out fee, across Liverpool, Campbelltown and Camden.
I’d rather you kept that money. Here’s what I’d check, in the order I’d check it.
If you’ve got no hot water, check the simple things first: the circuit breaker for an electric tank, the gas supply and pilot light for gas storage, and the error code on a continuous flow unit. Then look at the tank. A drip from the pressure relief valve is normal; water streaming from the tank body means the cylinder has failed and needs replacing. If power and gas are on and it’s still cold, call a licensed plumber.
Seven things to check before you pick up the phone
None of these need tools. Work through them in order.
1. The circuit breaker (electric storage)
Open the switchboard and look for the breaker labelled HWS, Hot Water or Off Peak. If it’s sitting off or halfway, flick it fully off and back on. If it holds, give the tank a few hours to reheat.
If it trips again straight away, or every day or two, stop resetting it. There are forum threads titled “hot water system tripping circuit breaker” that run for days, and the boring answer is nearly always a failed element letting water into the electrics. That needs a licensed tradie, not a stubborn thumb.
2. Off-peak timing
A lot of the older brick homes around Campbelltown and Liverpool have a big electric tank on an off-peak tariff, which your retailer calls a controlled load. The tank only gets power for a set window, mostly overnight.
Drain it with a round of 9 pm showers and there’s nothing left by morning. That’s not a fault. That’s a 315-litre tank meeting a family of six.
The newer estates around Oran Park and Gregory Hills have their own version: house two or three years old, hot water system not working, please come today. Often it’s working perfectly. It’s the tank that came with the house, meeting two teenagers, a toddler and a washing machine.
Regularly running out is a sizing conversation, not a repair. A tank that’s been fine for years and suddenly runs cold every morning is usually a dead bottom element or thermostat. That one is a repair.
3. Gas supply and the pilot light (gas storage)
First, is the gas actually on? Try the cooktop. If nothing’s getting gas, check the valve at the meter (handle in line with the pipe means open) and ring your retailer.
On LPG bottles, check the bottle. It happens to everyone once.
If the gas is fine, look through the little window near the bottom of the tank for the pilot flame. The relighting steps printed on the unit do work, provided you hold the button down for a good 30 seconds after it lights.
If the pilot light won’t stay lit after two or three goes, stop. More often than not it’s the thermocouple, a cheap part that tells the gas valve the flame is alive. That’s a quick fix for us and not worth a scorched eyebrow.
If you smell gas at any point, turn it off at the meter and call.
4. Error codes on a continuous flow unit
Continuous flow hot water (the box on the wall with no tank) needs mains power even though it burns gas, so check its breaker first. A power flicker can also freeze the controller: switch it off at the wall for a minute and back on.
If the controller shows an error code, write it down before you reset. A code that comes straight back is telling you something real, usually ignition or flame failure, and that’s a service call.
5. Is the pressure relief valve dripping, or streaming?
That copper pipe coming off the tank and running to the ground is the drain from the pressure and temperature relief (PTR) valve. A pressure relief valve dripping a little while the tank heats is normal; that’s expanding water going where it’s meant to.
A steady stream, or a drip that never stops, means the valve has worn out or something upstream has pushed the pressure up. Either way it’s a small, cheap fix.
What you don’t do is plug it. That valve is the reason your tank doesn’t become a rocket.
6. Is the tank itself leaking?
A hot water system leaking from a valve or a fitting is a repair. A hot water system leaking from the tank body, with water weeping from the base or the seams and rust streaks down the casing, is a replacement.
There is no patching a rusted steel cylinder. I’ve seen the silicone attempts, and they’re always brave.
Turn off the isolation tap on the cold inlet, switch off the power or gas, and if it’s pouring rather than weeping, treat it like any burst pipe and ring us.
Tanks rust once the sacrificial anode, a rod that corrodes so the tank doesn’t, is used up. Swapping it around the five-year mark buys years. Doing it at year twelve is sunscreen at four in the afternoon.
7. Lukewarm, not cold
Lukewarm is a different clue. On an electric tank it usually means one of the two elements has died, or the thermostat is on the way out. On gas, check the temperature dial hasn’t been knocked.
Before you blame the tank, run the kitchen tap. In NSW a tempering valve limits bathroom outlets to 50°C, and when it fails it can drop the bathrooms to lukewarm while the kitchen, which usually isn’t tempered, stays properly hot. Hot kitchen, tepid shower: it’s the tempering valve, not the tank.
Hot water system repair or replace: how I make the call
Start with the compliance plate, the sticker on the side of the tank with the manufacture date.
So, how long does a hot water system last? Roughly 8 to 15 years for a storage tank, depending on the water, the brand and whether anyone ever looked at the anode. Continuous flow units sit at the longer end if they’re serviced.
Under about eight years old with a dead element, thermostat, thermocouple or valve: repair it. Going by the Sydney 2026 price guides, a call-out fee sits around $69 to $170 and labour runs $92 to $230 an hour, most of it around $140, so a valve swap is a modest bill. I’ve written more on what plumbers charge in Sydney.
Over ten years old with a tank that’s leaking: replace it. Replacing a 12-year-old tank that’s leaking is not a repair job. It’s a replacement with a delay built in, and the delay costs you a second call-out and a wet laundry.
Electric vs gas vs heat pump hot water: what a replacement costs
Once it’s a replacement, the question is like for like or change horses. Your hot water system replacement cost moves with access, the state of the old valves and pipework, and any change of fuel, so treat these ranges as a starting point. Every job is quoted on inspection.
| System | Installed cost (Sydney 2026 price guides) | Running cost | Typical lifespan | Best for |
|---|---|---|---|---|
| Electric storage | $920 to $2,875 | Highest on a standard tariff; fair on off-peak | 8 to 12 years | Like-for-like swaps, off-peak homes, tight budgets |
| Gas storage | $1,375 to $4,025 | Moderate, and gas prices keep creeping | 8 to 12 years | Mains-gas homes that want fast recovery |
| Heat pump | $3,450 to $6,900 before rebates | Lowest; roughly a third of the power of a plain electric tank | 10 to 15 years | Families on electric storage, especially with solar |
| Continuous flow (gas) | Quoted on inspection; often needs a bigger gas line | Moderate; only heats what you use | 10 to 15 years, longer with servicing | Big households that never want to run out |
A like-for-like swap on a storage tank is normally a same day hot water replacement if you ring early and the unit’s in stock. A heat pump or a change of fuel takes more planning: a new circuit, a bigger gas line or a new spot for the unit.
Heat pump hot water rebates in NSW, and the fine print
The heat pump hot water rebate NSW homeowners keep hearing about is really two schemes stacked. As at mid-2026, the federal small-scale technology certificates (STCs) knock roughly $490 to $680 off, and the NSW Energy Savings Scheme adds up to about $640 if you’re replacing an electric system, or around $330 for gas. Combined, that’s roughly $900 to $1,350 off the price in the table.
The fine print: you pay a minimum $220 yourself, the unit has to go in through an accredited provider, and the figures move as the schemes wind down, so check before you count on them.
My opinion, for what it’s worth. Heat pumps are worth it for a lot of families on electric storage, provided the unit is a decent brand with a proper local warranty and it’s sited away from bedrooms.
They have a fan and a compressor, like a split-system outdoor unit, and they’ll happily run at 2 am. On the small blocks in Oran Park, the old tank often sits a few metres from the neighbour’s bedroom window. Think about where the noise goes before you think about the rebate.
If a unit is being offered for next to nothing, ask three things: what brand, what warranty, and who you ring when it stops on a Sunday in July.
When to call a plumber
You’ve done the seven checks. Here’s when to stop and ring someone, us or whoever comes up when you search “hot water plumber near me” at six in the morning.
- The breaker trips again as soon as you reset it.
- The pilot light won’t stay lit, or you can smell gas near the unit.
- Water is coming from the tank body, not a valve.
- The relief valve is streaming, or running scalding hot and constant.
- A continuous flow error code comes straight back after a reset.
- Power and gas are on, nothing has tripped, and it’s still cold.
The gas smell and the leaking tank can’t wait for Monday. Those are emergency plumber jobs, whatever the hour. The rest can usually hold until business hours, and it’s cheaper if they do.
In NSW, hot water work is licensed plumbing work, and anyone advertising it has to show their licence number. Check it. It takes thirty seconds.
We do hot water repairs and replacements across the Macarthur region and the Liverpool corridor, hot water repairs Campbelltown to Liverpool and everywhere between. Give us a call, tell us the brand and rough age, and we’ll tell you what to switch off while you wait.
Related guides: hot water system leaking and hot water system repairs.
Need it sorted? Ring 0455 222 292 any hour or book online. Monarch Civil & Plumbing is a hot water plumber, no call-out fee: repairs where they are worth it, same-day replacement where we can, and the NSW rebate sorted.
No hot water in Campbelltown, Liverpool or Camden?
Campbelltown has its own page: hot water service Campbelltown. For Liverpool, Camden and the rest of South West Sydney start with hot water systems, then the suburb pages plumber Liverpool and plumber Camden. Same-day replacement for common electric and gas sizes where stock allows, no call-out fee, NSW rebate sorted for heat pumps.
Frequently asked
Why is my hot water not working all of a sudden?
The usual suspects are a tripped circuit breaker on an electric tank, a pilot light that has gone out on gas storage, an error code on a continuous flow unit, or a tank that has used up its off-peak heating window. If power and gas are on and nothing has tripped, it is most likely a failed element, thermostat or thermocouple, which is a plumber's job.
How do I reset my electric hot water system?
Find the breaker marked HWS or Hot Water at the switchboard, flick it fully off, then back on. Allow a few hours for the tank to reheat, longer if it is on an off-peak tariff. If the breaker trips again straight away, do not keep resetting it. That usually means a failed element letting water into the electrics, and it needs a licensed tradesperson.
Is it normal for a hot water system to drip from the relief valve?
A small drip from the pressure and temperature relief valve while the tank is heating is normal; water expands as it warms and the valve lets a little out. A constant drip or a steady stream means the valve is worn or the pressure is too high, which is a cheap fix. Never cap or plug the drain line.
How long does a hot water system last?
Roughly 8 to 15 years for a storage tank, depending on brand, water quality and whether the sacrificial anode was ever replaced. Continuous flow units tend to last towards the longer end if they are serviced. Check the manufacture date on the compliance plate on the side of the unit; once a tank passes ten years, budget for replacement rather than big repairs.
How much does it cost to replace a hot water system in Sydney?
Going by Sydney 2026 price guides, an installed electric storage unit runs about $920 to $2,875, gas storage $1,375 to $4,025, and a heat pump $3,450 to $6,900 before rebates of roughly $900 to $1,350. Access, pipework upgrades and switching fuel all move the number, so every replacement is quoted on inspection.
Can I replace a hot water system myself in NSW?
No. In NSW, installing or replacing a hot water system is licensed plumbing work, and the gas and electrical connections need the right licence too. A DIY install can void the manufacturer's warranty and cause grief with insurance, and a badly fitted relief valve is genuinely dangerous. Do the basic checks yourself, then leave the install to a licensed plumber.
Licensed plumber and drainer based in Austral, 13+ years in the trade, working across Liverpool, Fairfield and the Macarthur region. About Paul