Electrical Why is there no hot water? Electrical faults explained
No hot water from an electric system can be an electrical or plumbing fault; note what you see and call a licensed electrician or plumber.
If an electric hot water system has stopped working, the cause could be electrical, such as the supply, a control or a heating part, or a water or plumbing problem. You should not open the system or work on it yourself. Note what you can see, then call a licensed electrician, or a plumber if water is leaking.
What can cause an electric hot water system to stop working?
An electric hot water system heats water with an electrical element, controlled by a thermostat. It may also be linked to a timer or an off-peak supply. If any part of that chain fails, you can end up with cold water.
Common causes include a loss of electrical supply to the unit, protection devices that have cut the power because of a fault, a failed element or thermostat, a timer or control problem, or a water-side fault such as a leak. You cannot tell which of these it is just by looking, and some of them involve live wiring.
Why shouldn’t I look inside it?
A hot water system combines mains electricity, hot water and pressure in one appliance. Covers are there to keep you away from live parts. Opening them, or touching the wiring, is dangerous and in Queensland the work is regulated.
Electrical work on a hot water system, such as the wiring, element or thermostat, must be done by a licensed electrician. Plumbing connections and valves are work for a licensed plumber. The Electrical Safety Office Queensland is the electrical regulator.
Who should I call: an electrician or a plumber?
- A licensed electrician for a system that has gone cold with no leak, repeated problems with the power supply, or anything involving the power connection, element or thermostat.
- A licensed plumber for leaks, dripping from the relief valve, or problems with water pipes and connections.
- The manufacturer for questions about the model, its manual or its warranty.
If you are not sure, describe what you see. A good tradesperson can tell you which fits.
What if I am renting?
Tell your landlord or property manager as soon as you notice, and let them arrange the repair. Do not arrange or attempt repairs yourself. If you have questions about your rights, the Residential Tenancies Authority is the place to ask.
Does it matter if I have solar or an off-peak tariff?
Yes, mention it. Some hot water systems are heated at set times, from solar surplus or from an off-peak supply, so the electrician needs to know how yours is set up. Do not touch any timers, controllers or isolators yourself.
It also helps to know if anything unusual happened beforehand, such as a storm, a power outage or a breaker that kept tripping. Our article on safety switches that keep tripping explains why that matters.
What to have ready when you call
Make and model
Read the make, model and serial number from the label, if you can see it without moving or opening anything, and photograph it.
What the display shows
If the system has a display, indicator light or error code, photograph it as it is.
When it stopped
Note when the hot water ran out, whether it happened suddenly or slowly, and if anything unusual happened before it.
Other signs
Note whether water is leaking, whether other things in the home are affected, and what you hear or smell.
Frequently asked questions
No. Wiring, element and thermostat work must be done by a licensed electrician in Queensland, and plumbing connections by a licensed plumber.
Call a licensed electrician if there is no leak and the system has simply gone cold. Call a licensed plumber if water is leaking or dripping.
Tell your landlord or agent promptly so they can arrange a licensed tradesperson. The Residential Tenancies Authority can answer questions about your rights.
It can be, because water near electrical parts is a hazard. Stay away, do not touch wet surfaces nearby and contact a licensed electrician and plumber.
They will usually want the make and model, any display or error code, when it stopped working and whether there is any leaking, smell or noise.
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