How electric storage systems work
An electric storage system heats water in an insulated tank using one or two elements, controlled by a thermostat. Water is stored at 60°C or more to prevent bacteria such as Legionella, then mixed down to a safe temperature by a tempering valve before it reaches the bathroom.
Common electric hot water faults
The usual faults are a burnt-out element, a failed thermostat, a tripped over-temperature cut-out, a worn relief valve and, eventually, a leaking tank. Lightning and power surges in the wet season are a common cause of sudden element and thermostat failures.
Off-peak or continuous?
Off-peak tariffs heat water overnight or at set times at a cheaper rate, but the tank needs to be big enough to last the day. Continuous tariffs can use a smaller tank but cost more per unit of power. If you have rooftop solar, a timer that heats water in the middle of the day can be a cheaper option still, and a heat pump uses far less power than a standard electric tank.
Electric hot water replacement
Replacing an electric tank like for like is usually the quickest and lowest-cost hot water job, and is often done the same day. We match the size to your household and your tariff, and fit a new tempering valve where required.
Electric hot water repairs
Elements, thermostats, over-temperature cut-outs and relief valves are all replaceable. If the tank itself is leaking, it needs replacing.
How long a new tank takes to heat
A new 250 litre electric tank usually takes around 3 to 4 hours to heat from cold on a standard circuit, or until the next off-peak period. See heat-up times by system type.
Electric hot water installation cost
Supply and install for a standard electric storage system is the lowest-cost option upfront. See the cost guide for typical ranges, and heat pump vs electric hot water to compare running costs.
Recent jobs
Common questions
How long does an electric hot water system last?
Most electric storage tanks last around 8 to 12 years. Regular relief valve checks and an anode replacement around the five-year mark can help a tank reach the upper end of that range.
Why does my hot water keep tripping the power?
A tripping safety switch often points to a failed element that is leaking current to earth. Don't keep resetting it. Turn the hot water isolator off and call a licensed plumber or electrician.
Can I keep my off-peak tariff with a new system?
Yes. A replacement electric storage tank can be connected to the same off-peak circuit. If you switch to a heat pump, we'll check that the model you choose suits your tariff.
Sources and further reading
- Business Queensland: hot water systems (temperature control devices on new and replacement systems)
- QBCC: Form 4 notifiable work (installing, replacing or removing a water heater)
- Clean Energy Regulator: solar water heaters and air source heat pumps (STC eligibility)
- Residential Tenancies Authority: emergency and routine repairs
Electric hot water near you
We cover every suburb on the Sunshine Coast and in Noosa. Popular areas include: