Hot Water System Replacement Cost in Australia (2026)

When your hot water dies, the two questions are always the same: do I repair or replace it, and what will a new one cost. Here is a straight 2026 guide to both, with indicative figures rather than a one-size number, because the right system depends on your home.

TL;DR

In Australia, expect roughly $1,200 to $2,500 for electric storage, $1,400 to $3,200 for gas, and $3,500 to $4,500 for a heat pump before rebates. Under 8 years old with a valve or element fault, repair. Over 10 years, or leaking from the tank, replace.

What each type costs (supply and install)

These are indicative 2026 ranges including GST, not a quote. The exact price depends on the unit, your existing connection, and access.

Electric storage: $1,200 to $2,500. The cheapest to buy and quickest to swap. More expensive to run than the alternatives.
Gas storage or continuous-flow: $1,400 to $3,200. Continuous-flow (instantaneous) never runs out and saves space; needs natural gas or LPG. Gas work must be done by a licensed gas fitter, which Josh is.
Heat pump: $3,500 to $4,500 before rebates. Dearest up front, cheapest to run. Rebates and STCs bring the real cost down a lot (see our heat pump rebates guide).
Solar hot water: $3,000 to $6,000. Roof collectors plus a tank and a gas or electric booster. Strong long-term saving on the Central Coast, higher install cost.

What moves the price

Changing connection type. Going from electric to gas, or fitting a continuous-flow unit, can mean new gas or water lines and is more involved than a like-for-like swap.
Where the unit lives. A tight or high spot, or moving the unit, adds labour.
Removing the old unit. We take the old system away and dispose of it as part of the job.
Tempering valve and compliance. Current rules require a tempering valve to limit the temperature at the tap; if yours is missing or old, it is replaced.

Repair or replace?

The honest rule of thumb:

Under about 8 years old, single fault: repair. A failed element, thermostat or relief valve is a routine fix and usually worth it.
Over 10 years old: lean towards replace. Once a tank is past its design life, throwing money at it rarely pays back.
Leaking from the tank itself: replace. A rusted-through tank cannot be repaired, only patched, and it will fail again soon.

Because Donza Plumbing carries common gas and electric units, we can often replace same-day, so you are not left without a hot shower while parts are ordered. That same-day hot water swap is the thing Josh does most.

We quote both the repair and the replacement, plus the running-cost difference, so you can decide with the real numbers in front of you. Request a callback or see our hot water systems service.

Common questions

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

As a 2026 guide, an electric storage unit runs about $1,200 to $2,500 supply-and-install, a gas storage or continuous-flow unit about $1,400 to $3,200, and a heat pump about $3,500 to $4,500 before rebates. The final figure depends on the unit, whether the connection type changes, and access. We confirm a fixed price before we start.

Should I repair or replace my hot water system?

If the unit is under about 8 years old and the fault is a valve or element, repair is usually worth it. Over 10 years old, or leaking from the tank itself, and replacement is the honest call: a leaking tank cannot be repaired, and pouring money into an old unit rarely pays off.

What is the cheapest hot water system to run?

A heat pump is the cheapest to run day to day because it moves heat rather than making it, using roughly a third of the power of an electric storage unit. It costs more up front, but rebates close a lot of that gap. Gas continuous-flow is the next most efficient and a good fit where you have natural gas.