How long should a hot water system last?

The short answer

Ten to fifteen years for a storage unit, often longer for continuous flow because there is no tank to corrode. Rusty water, pooling underneath or running out sooner than it used to are the signs it is near the end.

TradieAnswers editorial · written in-house and sourced to the authorities listed below

Checked against 3 published sources, listed in full at the end of this page. How we source this

Storage hot water systems fail from the inside out. The tank corrodes, slowly, protected by a sacrificial anode that itself wears away. When the tank finally goes, it goes all at once and usually onto a floor.

Typical service life

Type	Typical life	What usually ends it
Electric storage	10 to 15 years	Tank corrosion
Gas storage	8 to 12 years	Tank corrosion, then burner components
Gas continuous flow	15 to 20 years	Heat exchanger or electronics
Heat pump	10 to 15 years	Compressor or tank
Solar with electric boost	15 to 20 years on collectors	Tank first, collectors last

Signs it is near the end

Rusty or discoloured hot water, which usually means the tank lining has failed.
Water pooling under or around the unit.
Running out of hot water noticeably sooner than it used to.
The relief valve discharging frequently rather than occasionally.
Banging or rumbling from the tank, which is sediment.

Maintenance that extends it

The sacrificial anode in a storage tank is a replaceable part that corrodes so the tank does not. Having it checked around the five-year mark, and replaced if needed, is the single thing that most extends tank life. It is rarely done, because nobody thinks about a hot water system until it stops working.

Who does this work

You need a licensed plumber

Because replacing a hot water system involves the water connection and the gas or electrical connection, all of which are licensed.

This is licensed work in every Australian state and territory. Check a licence in your state

Where are you?

Who regulates plumbing and gas in your state

Trade regulation in Australia is state law, so the body that answers this depends on where the work is. Pick yours.

New South Wales — NSW Fair Trading: Plumbing, draining and gasfitting are separate licence classes. Work must be notified and is subject to inspection. How to check a licence in NSW
Victoria — Building and Plumbing Commission: Licenses and registers plumbers across separate classes of work. Licensed plumbing work generates a compliance certificate you should be given. How to check a licence in VIC
Queensland — Queensland Building and Construction Commission: Licenses plumbers and drainers. Notifiable work must be submitted to the QBCC after completion. How to check a licence in QLD
Western Australia — Building and Energy: Plumbing contractor and tradesperson licensing, and gasfitting authorisation, sit with the same body. How to check a licence in WA
South Australia — Consumer and Business Services: Plumbing and gas fitting are treated as building work but need specific plumbing, gas fitting and electrical licence classes, known as PGE. How to check a licence in SA
Tasmania — Consumer, Building and Occupational Services: Plumbers, gasfitters and auto gasfitters are licensed occupations, all searchable in one place. How to check a licence in TAS
Australian Capital Territory — Access Canberra: Plumbers, drainers and gasfitters are licensed construction occupations in the ACT. How to check a licence in ACT
Northern Territory — Plumbers and Drainers Licensing Board: Holds the list of currently licensed plumbers and drainers. The board can also confirm a licence by phone if a name is not appearing. How to check a licence in NT

Sources

Every source below was fetched and its response recorded on the date shown. Where a government site blocks automated clients, that is noted rather than reported as a successful check.

Hot water systems · energy.gov.auChecked 2026-08-10 · responded 200 OK
Hot water systems · Your Home (Australian Government)Checked 2026-08-10 · responded 200 OK
Hot water rebate · Solar VictoriaChecked 2026-08-10 · responded 200 OK