Why Is My Hot Water Not Working? (Troubleshooting)

If your hot water isn't working, the most common causes are a tripped switch or failed heating element on electric systems, or a pilot light that's gone out on gas systems. Start by checking whether the problem is with the whole house or just one tap, then run through the safe checks below. Some fixes are simple; anything involving gas, electrical wiring or a leaking tank is a job for a licensed professional.

First, narrow it down

Before touching anything, work out what's actually happening:

No hot water anywhere? The problem is the hot water system itself.
No hot water at just one tap? It's more likely a tap, mixer or valve issue — see our tap and fixture repairs.
Lukewarm or running out fast? Points to a thermostat, element or an undersized/ageing system.
Discoloured or smelly hot water? Could be a corroding tank — see how long hot water systems last.

Electric hot water troubleshooting

If you've got an electric system, run through these safe checks:

Check the switchboard. A tripped circuit breaker or safety switch is a common culprit. Reset it once. If it trips again straight away, stop — that's a fault that needs an electrician or plumber, not repeated resetting.
Check the isolation switch. Many electric units have a dedicated switch near the unit or switchboard. Make sure it's on.
Consider your tariff. If your system runs on an off-peak or controlled-load tariff, it only heats at certain times. After heavy use you may simply be waiting for the next heating cycle.
Look for leaks. Water pooling around the unit suggests a tank problem — turn it off and call a plumber.

If the power is on and there are no leaks but you've still got no hot water, the likely cause is a failed heating element or thermostat. These are inside the unit and involve electrical components, so they should be tested and replaced by a licensed professional — not opened up yourself.

Gas hot water troubleshooting

For a gas system, check these first:

Is the gas on? Confirm the gas supply is on at the meter and any isolation valve near the unit, and that other gas appliances are working. If nothing gas-powered works, the issue is the supply.
Check the pilot light (older storage units). If it's gone out, follow the relighting instructions printed on the unit exactly. If it won't stay lit, or you smell gas at any point, stop and call a licensed gas fitter.
Continuous-flow units often show an error code on a display or controller. Note the code — it helps the plumber diagnose the fault quickly.
Check for a tripped controller if your continuous-flow unit has a temperature controller with a power supply.

Important: if you smell gas at any stage, treat it as an emergency. Don't relight anything — follow our guide on what to do in a gas leak and call a licensed gas fitter.

Continuous-flow error codes are genuinely useful, so it's worth writing the code down before you reset or call. Different codes point to different faults — ignition failure, a water-flow issue, overheating, a sensor fault — and giving the plumber the code over the phone often means they can arrive with the right part and fix it in one visit rather than two.

Checks that apply to both

A few causes affect gas and electric systems alike, so run through these before assuming the worst:

Cold snap? In very cold weather it can take longer to heat, and outdoor units can occasionally be affected. Water coming into the tank is colder, so the system has more work to do.
Recently ran out? A storage system that's been drained by lots of use — several showers in a row, or the washing machine running hot — just needs time to reheat. This isn't a fault, it's capacity.
Blocked or closed valve? Make sure the cold water supply to the unit is turned on. If someone has recently done work nearby, a valve may have been left closed.
Been away? Some systems are switched off or run down during a holiday and simply need time to come back up to temperature.

Not enough hot water, rather than none?

If you're getting some hot water but it runs out too quickly or never gets properly hot, the cause is usually different from a total outage. It often points to a thermostat set too low, a partially failed heating element (electric units frequently have two, and one can fail while the other keeps working), sediment build-up reducing the tank's effective capacity, or simply a system that's now too small for your household. A licensed plumber can test which it is and advise whether a repair or a resize is the better fix.

When to call a plumber

Call a licensed plumber or gas fitter if:

The circuit breaker trips repeatedly
The pilot light won't stay lit
You see water leaking from or pooling around the unit
The water is discoloured, rusty or smells off
A continuous-flow unit shows a persistent error code
You smell gas at any point — stop and call immediately

Heating elements, thermostats, gas valves and tank leaks all need a licensed professional. It's not just about getting it right — in WA, gas work and most plumbing must legally be done by someone licensed, as we explain in do I need a licensed plumber in WA.

Still no hot water after these checks? Call our licensed Canning Vale plumbers and we'll get it sorted safely. For repairs and replacements, see our hot water systems service.

Frequently asked questions

Why has my hot water suddenly stopped working?

Common causes are a tripped switch or failed element on electric systems, or a pilot light that's gone out on gas systems. First check whether it's the whole house or one tap, then check the power or gas supply before calling a plumber.

How do I relight my gas hot water pilot light?

Follow the relighting instructions printed on the unit exactly. If it won't stay lit after a couple of attempts, or you smell gas at any point, stop immediately and call a licensed gas fitter — don't keep trying to relight it.

My hot water breaker keeps tripping — what's wrong?

A breaker that trips once may just need a reset, but one that trips again straight away signals a fault, often a failed heating element or wiring issue. Don't keep resetting it — have a licensed professional test and repair it.

Can I fix a hot water element or thermostat myself?

No. Heating elements, thermostats and gas valves involve electrical or gas components and must be tested and replaced by a licensed professional. In WA this work legally requires a licensed plumber or gas fitter for safety and compliance.