How much does it cost to replace a hot water system in Australia?

What’s The Damage gives supply-and-install prices, low / typical / high (updated October 2026):

• Electric storage: $800 / $1,800 / $3,000
• Gas storage: $1,200 / $2,200 / $3,500
• Continuous flow gas: $1,500 / $2,200 / $3,500
• Heat pump: $3,000 / $4,200 / $6,000 before rebates; $2,500 / $3,600 / $5,300 after rebates
• Solar hot water: $3,500 / $5,000 / $7,000
• Urgent same-day like-for-like replacement: $1,300 / $2,300 / $4,000

It lists starting prices of $760 installed in Sydney and $840 in Melbourne. These are published estimates, not quotes.

1. Like-for-like or a change of type. Swapping an old tank for the same kind in the same spot is the simplest job. Switching from electric to gas or to a heat pump can mean new gas pipe, electrical work or a new location.
2. The type of system. Electric storage is cheapest to buy; heat pumps and solar cost more up front. Running costs differ too, so ask your plumber to compare them for your household.
3. Size. Ask the plumber to size the unit to how many people live in the home, not just to match the old one.
4. Urgency. If the old unit has failed and you need hot water today, expect to pay more and have less choice.
5. Access. A tank in a tight cupboard, roof space or upstairs takes longer than one on an outside wall.
6. Extras and rebates. Valves, disposal of the old unit and electrical work can be separate lines. Rebates for heat pumps and solar change, so check your state government’s energy website and ask whether a quote is before or after rebates.

• NSW: the NSW Government says you need a licence or certificate to do any plumbing, draining or gasfitting work, regardless of the cost of the work.
• Victoria: the Building and Plumbing Commission says a compliance certificate must be issued for plumbing work worth more than $750 in total (materials, appliances, labour and GST, whoever supplied them), and for some types of work whatever the value. It must be given to you within five days of finishing the work. Keep your copy.

For every state’s register, see our guide to checking a tradie’s licence.

• Get two or three written quotes for the same system: same type, same size, same location.
• Check whether removal of the old unit, valves and any electrical work are included.
• For heat pumps and solar, ask whether the price is before or after rebates, and who lodges the paperwork.
• For gas units, ask who does the gasfitting and whether they are licensed for it.
• Ask what warranty applies to the unit and to the installation.