Hot water heater maintenance: what you can check, and what you leave alone
Most hot water systems ask very little of you. A few quick looks each year catch problems early, and the rest belongs to a licensed plumber.
Hot water heater maintenance is mostly looking, not doing. Once or twice a year you check for leaks, listen for new noises and make sure the pipework is dry. Anything involving the relief valve, the anode, gas parts or the tank cover is for a licensed professional.
Many households do nothing until the water runs cold. That is a fair description of how most systems fail, and a short yearly check is cheap insurance against it.
What can you check yourself?
- Look for drips. Check the base of the tank, the pipe joints and the pipe from the relief valve. A small intermittent drip from the relief pipe can be normal on some systems, but a constant flow is not.
- Look for rust and staining. Marks around fittings or on the tank jacket suggest slow leaks.
- Listen. Popping, banging or rumbling can point to scale or sediment. Our page on a leaking hot water system covers the wetter symptoms.
- Check the water. Rusty or smelly hot water, but clean cold water, points at the tank.
- Read the label. Note the model, the age and the warranty terms so you have them when a fault appears.
Which parts need a licensed plumber?
| Part | What it does | Who touches it |
|---|---|---|
| Relief valve | Vents pressure and heat safely | Licensed plumber only. See how the relief valve works |
| Tempering valve | Limits the hot water temperature at taps | Licensed plumber. See the tempering valve page |
| Sacrificial anode | Corrodes first to protect the tank | Licensed plumber. See the sacrificial anode |
| Thermostat and element | Heat the water on electric systems | Licensed professional only |
| Burner, pilot and flue | Heat the water on gas systems | Licensed gasfitter only |
Do not lift the relief valve lever to test it yourself. That job belongs to the plumber who services the system.
How often should it be serviced?
Follow the maker's manual and your warranty terms. Many makers expect a periodic service by a licensed plumber, and a missed service can complicate a claim. Our guide to hot water system warranties explains what usually matters.
Is it worth paying for a service on a system that works? Often yes for older units, and less so for a new one still well inside its warranty. Ask what the visit includes before you book.
What is not worth doing
Flushing the tank on a schedule you invented, adjusting temperature settings, or wrapping the tank in extra material are all poor ideas unless the manual says otherwise. Insulating the pipework is fine, and our page on insulating a hot water system shows what is safe.
What should you do when the system gets old?
Age changes the maths. A storage tank that is well past ten years old is closer to the end of its life. And the sensible move is to plan rather than wait for a leak. Our page on how long hot water systems last sets out the usual ranges by type.
Keep a simple note with the install date, the model and the plumber's contact details. When the system fails on a cold morning, that note saves you an hour of hunting. It also makes a warranty claim much easier.
Signs you should call someone now
- Water pooling around the tank. Turn the system off as described in our emergency guide and call a licensed plumber.
- Hot water that is brown or smells of metal. This can mean the tank is corroding from inside.
- A relief valve that runs constantly. The system is telling you something is wrong with pressure or temperature.
- Any smell of gas. Leave the building and call the gas emergency number from outside.
None of these are signs to wait and see. A quick call costs far less than a failed tank.
Frequently asked questions
How often should I maintain my hot water heater?
Look it over once or twice a year for leaks, rust and new noises, and book a licensed plumber for a service as your manual and warranty suggest.
Can I flush my hot water system myself?
Only if the manual says so and you know how to isolate it safely. Draining the tank is generally work for a licensed plumber, so ask before you try.
Is it normal for the relief valve pipe to drip?
A small intermittent drip while the water heats can be normal on some systems. A steady or heavy flow is a fault, so call a licensed plumber.
Sources
What this page explains is based on these official sources. If you check one and it does not match what you read here, send it to us and the article gets corrected.
- Australian Government, energy.gov.au. Hot water systems — types, installation and energy performance
- Australian Building Codes Board. National Construction Code — Volume Three (Plumbing Code of Australia)