New water heater system: what to settle before the quotes arrive
Repair or replace, which type, what size and what every quote should include. Sort these first and the price comparison gets easy.
Do nothing in a hurry. That is the best advice when your hot water system dies and a salesperson is already on the phone. A new system is a ten to fifteen year decision, and the rushed choice is the one people regret.
This page covers what to settle before anyone quotes. It will not pick a brand for you. It will make sure the quote you get is for the right kind of system.
Is it time for a new system at all?
Not always. A failed thermostat, a worn valve or a dead element is a part, not a system. A tank that leaks from the body is different. Water escaping through the shell is usually the end of that unit.
Ask the plumber to name the failed part and say why it cannot be replaced. If the answer is vague, get a second opinion. Our guide to matching a symptom to a fault shows what to describe.
Which type suits your home?
The type decides almost everything that follows: running cost, space, installation work and what the quote includes. Work out the type before you compare prices.
| Type | Suits you if | Watch for |
|---|---|---|
| Electric storage tank | You want a simple, familiar system and can use off-peak supply | Slow recovery if the tank is too small |
| Gas storage or instantaneous | Mains or bottled gas is already connected | Flue and clearance rules; all gas work is licensed |
| Heat pump | You have outdoor space and want low running use | Noise near bedrooms and a cold-climate rating |
| Solar with a booster | You have a sunny, unshaded roof | Roof access and a working booster in winter |
Each type has its own page: heat pump, solar and gas. Read the one that fits before you ask for quotes.
Size it to the household, not the old tank
Copying the old tank size is the commonest mistake. Households change. A tank sized for five people is wasteful for two, and a small one that now serves a family runs out mid-shower.
Count the people who shower daily, note whether you have a large bath, and tell the plumber. They size the system from that, not from the label on the old one.
Check the rules before you buy
Replacing a hot water system is licensed work in every Australian state and territory. Your regulator also sets rules on tempering valves, water temperature at the outlet and, in some areas, what type may be installed. These rules differ between states.
A licensed plumber knows them. Ask which standards apply to your job, and ask for the certificate of compliance afterwards. Our page on the certificate of compliance explains what to expect.
Questions to put in every quote
- What type and capacity is being supplied, and why that size.
- What is included: removal of the old unit, a new tempering valve, pipework changes and any electrical or gas work by the right licence holder.
- The warranty: how long, what it covers and whether labour is included.
- The paperwork: the certificate of compliance and any rebate or incentive paperwork your state offers.
Get at least two quotes for the same type and size. Different types are not comparable, so compare like with like.
Frequently asked questions
How do I know I need a new hot water system?
A leak from the tank body is usually the end of that unit. A system that has simply stopped heating may need one part, such as a thermostat, a valve or an element. Ask the plumber to name the failed part before you agree to a replacement.
What type of hot water system should I choose?
It depends on your fuel supply, space, roof and climate. Electric storage is simple, gas needs an existing connection, a heat pump needs outdoor space and solar needs a sunny roof. Settle the type first, then compare quotes.
Can I install a new hot water system myself?
No. Installing or replacing a hot water system is licensed plumbing work in every Australian state and territory, and any gas or fixed electrical connection needs the right licence holder as well.
What should a hot water system quote include?
The type and capacity, removal of the old unit, a tempering valve, any pipework changes, the warranty terms and the certificate of compliance. Compare quotes for the same type and size only.
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
- NSW Fair Trading. Plumbers, drainers and gasfitters — licensing