There’s nothing quite like jumping in the shower and getting a blast of cold water to start your morning. If your hot water isn’t working, the good news is that many causes are surprisingly simple to diagnose, and some you can fix yourself in minutes. Others need a licensed plumber or gas fitter, and a few require you to act fast for safety reasons.
This guide walks you through exactly what to do, starting with the safety checks you should never skip.
Key Takeaways
- If you smell gas near your hot water system, don’t touch anything. Evacuate and call 000 or your gas supplier immediately
- The most common cause of hot water not working is a tripped circuit breaker (electric) or an unlit pilot light (older gas systems)
- Hot water accounts for up to 25% of a typical Australian household’s energy use, so an inefficient or failing system is worth sorting quickly
- Most storage systems last 8–15 years; if yours is in that range, age could be driving the problem
- When in doubt, call a licensed plumber. Hot water systems involve high-voltage electricity or gas, and both carry serious risks
Safety First: Warning Signs You Shouldn’t Ignore
Before you start checking anything, run through this list. If any of these apply, stop and call a professional straight away. Gas system warning signs:
- You can smell rotten eggs or sulphur near the unit
- There’s a hissing sound coming from the gas line
- The area around the system feels unusually warm
- You can see visible flame or scorching you haven’t noticed before
If you smell gas, don’t turn any lights or appliances on or off, don’t use your phone near the unit, open windows and doors, leave the building, and call 000 or your gas supplier. Never attempt to relight a pilot light or inspect gas components when you suspect a leak. Electric system warning signs:
- Burning smell from the unit or electrical panel
- Visible water pooling under or near the system
- Sparking or unusual sounds from the electrical connections
Water and electricity are a dangerous combination. If your electric system is leaking, switch off the power at the breaker before touching anything.
Quick Checklist: Try These Before Calling a Plumber
If there are no safety concerns, work through this checklist. It covers the most common reasons for no hot water and takes less than five minutes. For electric systems:
- Check your circuit breaker – has it tripped?
- Reset the breaker and wait 30–60 minutes for the tank to reheat
- Press the reset button on the unit (usually near the thermostat panel)
- Check whether a power outage has affected your off-peak supply
For gas systems:
- Is the pilot light out? (Check your manual for relighting instructions.)
- Is the gas valve open?
- Has your gas account been disconnected, or are there works on the line in your area?
- Is there an error code on the display? Note it down before calling
For all systems:
- Is the cold water supply valve to the unit fully open?
- Have you recently had unusually high demand (guests, multiple loads of washing)?
- Has the temperature pressure relief (TPR) valve been triggered?
If none of these resolve your hot water not working issue, read on for system-specific guidance.
Electric Hot Water System Not Working
Electric storage systems are the most common type in Australia, with around 50% of Australian households using them. They’re reliable, but a few things tend to fail.
Tripped Circuit Breaker
This is the single most common cause of no hot water in an electric system. Head to your switchboard and look for a breaker that’s in the middle or “off” position. Flip it fully off, then back on. Give the system an hour to heat before testing.
Tripped Reset Button (Energy Cut Off / ECO Switch)
Most electric hot water systems have a high-temperature safety switch that trips if the water overheats. It’s usually behind the access panel near the thermostat. Press it to reset. If it keeps tripping, the thermostat is likely faulty, and you need to call a plumber.
Failing Heating Element
Electric tanks typically have both an upper and a lower heating element. When one fails, you’ll often get some hot water, but it runs out much faster than normal. Replacing an element isn’t expensive, but it does require a licensed electrician or plumber.
Thermostat Issues
If your water is too hot or not hot enough (but is heating), the thermostat is a likely culprit. The recommended setting in Australia is 60°C at the storage tank to prevent bacterial growth, with a tempering valve to reduce the temperature at the tap to 50°C for safety.
Gas Hot Water System Not Working
Both storage and continuous flow gas systems have their own set of failure points.
Pilot Light Out
Older gas systems use a standing pilot light. If it goes out, there’s no ignition source to heat the water. You’ll usually find relighting instructions on a label attached to the unit. If the pilot won’t stay lit after a few attempts, the thermocouple (a small safety sensor) is probably worn out and needs to be replaced.
No Gas Supply
Check that the gas valve on the line to your system is fully open. If you have LPG bottles, check they’re not empty. If neighbours are also experiencing issues, there may be a supply problem – contact your gas provider.
Gas Control Valve Fault
The gas control valve manages gas flow to the burner. If it’s faulty, the system either won’t fire or won’t maintain temperature. This component must be repaired or replaced by a licensed gas fitter.
Dirty or Blocked Burner Assembly
Dirt and debris can affect the flame, reducing efficiency or preventing ignition entirely. A licensed technician can clean or replace the burner. If your system runs but the hot water isn’t working at full temperature, a partially blocked burner is worth investigating.
Continuous Flow (Instantaneous) Hot Water Not Working
Continuous flow systems are popular on the Sunshine Coast and generally reliable. When they play up, the fix is usually simpler than you’d expect.
Check For an Error Code
Modern continuous flow units display error codes when something is wrong. Note the code and cross-reference it with your manual. Common codes indicate ignition failures, flow sensor faults, or temperature sensor errors.
Check the Flow Rate
Instantaneous systems need a minimum water flow to activate. If multiple taps or outlets are running simultaneously, or if there’s a restriction in the cold water supply, the unit may not trigger. Try running a single tap fully open.
Check the Gas Supply
As with storage gas systems, a closed valve or empty LPG cylinder is a simple fix that’s easy to overlook.
Inlet Filter Blocked
Most continuous flow units have a small filter at the cold water inlet. If it’s blocked with sediment, flow is restricted, and the unit won’t fire. A plumber can clean or replace this quickly.
If these checks don’t restore your hot water, hot water plumbing issues in continuous flow systems often come down to internal components like the heat exchanger or flow sensor, both of which require a licensed technician.
Could Your System’s Age Be the Problem?
If you’ve worked through the checklist above and your hot water is still not working, it’s worth considering how old your system is. Hot water systems often show declining performance before they stop completely.
General lifespan benchmarks in Australia:
- Electric storage: 10–15 years
- Gas storage: 8–12 years
- Continuous flow (gas): Up to 20 years with maintenance
- Solar: 15–20+ years
- Heat pump: 10–15 years
If your system is approaching or beyond these ranges, repairs may only delay the inevitable. Weigh up the cost of the repair against the unit’s age – sometimes replacing it is the smarter call. A licensed plumber can give you an honest assessment.
How to Prevent Hot Water Problems
A little maintenance goes a long way. Here’s what to do each year to avoid the frustration of no hot water at the worst possible time: Annual checks:
- Inspect the temperature and pressure relief (TPR) valve – it should lift and release easily, with no constant dripping
- Flush sediment from the tank base (especially in older electric storage units)
- Check all connections and valves for signs of corrosion or leaking
Every 2 – 5 years:
- Have a licensed plumber inspect the sacrificial anode in your tank, which prevents internal corrosion and should be replaced when depleted
- Full service of gas system components, including burner and gas valve inspection
On the Sunshine Coast, the combination of warm climate and variable water quality means sediment can build faster than in cooler parts of Australia. Staying on top of annual checks is genuinely worth it.
When It’s Time to Call a Professional
You’ve been thorough, but if your hot water system repairs are beyond what the checklist can solve, it’s time to bring in a licensed plumber or gas fitter. Some situations that always require a professional:
- Gas smell or suspected leak
- Water leaking from the tank or connections
- Electrical fault or tripping breaker that won’t reset
- Any repair to internal components (heating elements, thermostats, gas valves)
- Installing or replacing a unit
Still No Hot Water? Let’s Sort It Out
Working through this guide and still stuck? That’s usually a sign the problem is internal – a failing component, a gas fault, or a system that’s simply reached the end of its life. The good news is it’s rarely as complicated (or as expensive) as it sounds once a licensed plumber takes a look.
Universal Plumbing N Gas services the Sunshine Coast and Brisbane for all hot water system repairs – electric, gas, and continuous flow. We offer free quotes, honest advice on whether to repair or replace, and prompt response times so you’re not left without hot water longer than necessary.
Call us on 0439 644 483 or get in touch online to book your free quote today.
FAQs
The most common causes are a tripped circuit breaker (in electric systems), a pilot light that’s gone out (in older gas systems), or a safety switch on the unit that’s been triggered. Work through the checklist above. If you can’t identify the cause within a few minutes, call a plumber rather than guessing.
For electric systems: locate the reset button on the thermostat panel (usually behind the access cover) and press it firmly. For the circuit breaker, flip it fully off and back on.
For gas systems with a pilot light, your unit will have a relighting procedure on a label. Typically, you hold the gas valve knob to “pilot”, ignite, and hold for 30–60 seconds before releasing.
For continuous-flow units, consult the manual for your error code, or simply power-cycle the unit. If resetting doesn’t hold, there’s an underlying fault that needs to be diagnosed.
It depends on the type.
- Electric storage units typically last 10–15 years
- Gas storage systems 8–12 years
- Continuous flow units up to 20 years (with regular servicing)
- Solar systems 15–20+ years
Regular maintenance, particularly annual TPR valve checks and anode rod replacement every five years, significantly extends system life.
For electric systems, it’s a tripped circuit breaker or a failed heating element. For gas systems, it’s an unlit pilot light or a faulty thermocouple. Sediment buildup in storage tanks is a common long-term problem across all storage system types, reducing efficiency and eventually causing component damage.
As a general rule, if the system is under 8–10 years old and the repair is straightforward (thermostat, element, thermocouple), repair is usually worth it. If it’s older than its expected lifespan and showing multiple issues, or if the repair cost approaches 50% of replacement cost, replacement is typically the better investment, especially since newer systems are considerably more energy-efficient. A licensed plumber can give you a clear breakdown of both options.
Disclaimer: The information in this article is provided as a general guide only and does not constitute professional plumbing advice. In Australia, plumbing work beyond basic maintenance (such as replacing tap washers) must be carried out by a licensed plumber. Regulations vary by state and territory – always check with your local authority before attempting any plumbing work. Unlicensed plumbing work may void your home insurance and result in fines. If you are unsure about any step in this guide, please contact a licensed plumber.