Safe observations for electric hot water and other existing systems, with a clear point to stop and seek an appropriately licensed assessment.
| Symptom | Most likely cause |
|---|---|
| No hot water at all | Thermostat or heating element failure |
| Water only ever warm | Tempering valve mixing too much cold |
| Breaker keeps tripping | Failed heating element or thermostat |
| Water pooling around the tank | Internal tank corrosion |
| System older than 15 years | Replacement usually the better option |
Match your symptom to the most likely cause, then work through the safe checks below for your system type.
These are possible causes, not a remote diagnosis. Supply issues and more than one fault can produce similar symptoms.
One of the most common faults on electric storage systems. The thermostat tells the element when to heat; when it fails it either stops calling for heat altogether or sticks on and trips the safety cut-out.
Licensed work — the terminals behind the cover are live.
Elements are a wear item — they scale up and eventually burn out. In a twin-element tank, a fault in either circuit can affect the amount of hot water.
Requires an appropriately licensed trade; price and parts need confirmation.
If the water is warm rather than properly hot, the tempering valve may be mixing too much cold water into the hot supply. A contractor must confirm whether mixing or another fault is responsible.
Licensed work — it is a scald safety device and must be set correctly.
Sometimes it really is just a tripped breaker at the switchboard. Reset it once. If it trips again, stop resetting and seek licensed assessment; the cause is not confirmed.
Only reset once if the switchboard is dry and safe. A repeat trip needs a licensed trade.
Compare cylinder condition, repair history, warranty and complete quotes. Age alone does not establish whether repair or replacement is suitable.
Compare confirmed faults, warranty and contractor quotes before spending.
If you can see water pooling, hear running water inside a cabinet, or smell gas, stop troubleshooting. Keep clear of water near electrical fittings. For a leaking tank, close the cold-water isolation valve and switch off its dedicated power or gas supply only if safe. Do not run an electric element in an empty tank. If you smell gas, avoid electrical switches, leave the area and contact your gas supplier from a safe location. Read about hot water repairs or, if the cylinder itself has failed, hot water replacement.
Anything involving opening a thermostat cover, gas components, or the sealed parts of a heat pump is licensed work. If the checks above have not restored hot water, the cause needs licensed assessment. Read about hot water repair, and if the tank is old, read the repair or replace guide first. Related symptoms are covered in common hot water problems.
Some households run controlled or off-peak electric tanks where their retailer offers them, so a cold morning can be a tariff question before it is a fault. Properties beyond the mains gas network run on LPG, where an empty or cold bottle mimics an appliance failure. Heat pumps installed in tight side passages can lose the airflow they need, and outdoor units on exposed positions can lose pilots to wind. None of these are faults with the appliance itself, and all are worth ruling out first.
Explore the questions for your hot water enquiry.
Contact number: Call 07 4580 2422
Most “no hot water” problems come down to the same short list. Very few are exotic faults — most are wear items reaching the end of their life.
Maintenance requirements vary by model. Use the manufacturer manual and ask a suitable licensed trade before attempting any maintenance.
The pressure and temperature relief valve is a safety device. Do not block its drain or alter it. Follow the exact model manual for inspection requirements; discharge can be scalding. If unsure, leave operation to an appropriately licensed trade.
If it will not seat again afterwards, or it drips continuously, the valve is due for replacement. That is licensed work and should be booked in rather than left running.
The anode is a rod that corrodes so the steel cylinder does not. It is consumed over time, and once it is gone the tank starts eating itself. Most homeowners never replace it — which is precisely why so many tanks fail from the inside out.
Inspection intervals and anode requirements vary by model; follow the manufacturer manual. It is a plumber's job: the tank must be isolated and drained down before the rod comes out.
Check the model manual for operating limits and any cold-weather protection. Observe exposed pipework for damage, but do not alter relief drainage, wiring or gas connections. Heat pump airflow and condensate drainage need to stay clear.
Local water quality varies by suburb, and sediment can still build up in storage tanks over years of use regardless of conditions. Worn or corroded parts are a more common cause of failure than blockages.
Age is the single best predictor. Use it as a first filter before you spend anything on parts.
Check the actual warranty terms and fault before comparing repair options.
Elements, thermostats and valves are wear items and are worth replacing at this age.
A cheap part is fine. A major repair on an ageing tank rarely pays for itself.
The tank is past typical service life; the next failure is likely to be the cylinder itself.
Want the full breakdown, including what each option typically costs? Read the repair or replace guide and the replacement cost guide.
On an off-peak electric system, the tank reheats overnight — if the element or thermostat failed during the day you will notice it the next morning. Check the hot water circuit at the switchboard first; if it has tripped, a trip may indicate a fault and does not establish which component has failed. Do not keep resetting it.
Continuous flow units display a code that identifies the fault area — ignition, flame failure, overheat or water flow. Turning the unit off at the isolation switch for a minute can clear a one-off lockout, but a repeating code needs an appropriately licensed gas professional.
Only follow the manufacturer's instructions printed on the unit, and stop immediately if you smell gas. If the pilot will not stay lit, the thermocouple or gas valve is the likely fault and needs a licensed gas fitter.
Outdoor conditions can affect some models; check the specific manual. Continuous flow units only run their built-in frost or cold-weather protection while they still have power, so a unit switched off at the isolation point can be more vulnerable. LPG bottles can also drop pressure on cold mornings, which looks exactly like an appliance fault.
Recovery depends on capacity, element output, inlet temperature and the model. Check the manual rather than assume a universal waiting time. On an off-peak tariff it will not reheat at all until the off-peak period starts, which is why the problem is often noticed the following morning.
If safe checks do not explain the problem, an appropriately licensed contractor needs to assess the system. No local contractor is currently approved through this website; online enquiries remain disabled.
No local contractor is currently approved; online enquiries remain paused.
