Hot water system replacement cost in Melbourne

Melbourne prices, checked in September 2026.

Figures from What’s The Damage, Melbourne plumber costs, September 2026. This is one of the jobs sitting behind the numbers in our guide to how much a plumber costs in Melbourne.

What each type costs installed

The spread above is real, and most of it isn’t the unit. It’s what the unit needs once it’s there.

A like-for-like swap is the cheap end of any row. The connections are already in the right place, the flue is already sized, and the old one comes out as the new one goes in. That’s a morning’s work and a predictable number.

The dear end is where something has to change. Moving the unit, running a new gas line, upgrading a flue, adding a tempering valve that was never there, or getting a heat pump onto a base with enough clearance around it. None of that is the plumber being creative. It’s the job the house turns out to need.

What actually moves the number

• Whether the new unit goes where the old one was
• Whether the gas line and flue suit the model you've chosen
• Whether a tempering valve needs adding or replacing
• Access, especially anything in a roof space or down the side of a terrace
• Removal and disposal of the old unit

The Victorian rebate, and who actually gets it

Victoria runs a Solar Homes hot water rebate of up to $1,000, or up to $1,400 if you pick an approved Australian-made system. It’s a 50% rebate on the purchase price, applied after other discounts.

The catch is who it’s for, and it’s tighter than most people assume. You need to be an owner-occupier of an existing home, with a household income under $150,000 a year. That cap came down from $210,000 on 1 July 2026, which caught a lot of people out.

The property also has to be valued under $3 million. The unit you’re replacing has to be at least three years old, and the address can’t have claimed a hot water or solar battery rebate before.

It only covers heat pumps and solar hot water. Gas doesn’t qualify, and neither does a straight electric element.

There’s a separate Victorian Energy Upgrades discount that installers apply at the point of sale, and the two programs can stack. Your installer handles that one rather than you.

Before you count on the rebate

• Check eligibility on the Solar Victoria site first, not on an installer's word
• You must buy through an authorised retailer, using a listed product
• Installation has to happen within 120 days of your eligibility code

If the rebate is the thing making a heat pump affordable for you, confirm you qualify before anyone orders a unit. It’s a miserable conversation to have afterwards.

Should you switch types, or replace like for like?

Like for like is nearly always cheaper on the day. That’s the honest answer and it’s why most changeovers are exactly that.

Switching is worth looking at in two situations. If your unit has died and you were planning to move it anyway, the labour is being spent regardless. And if you qualify for the rebate, a heat pump’s install cost comes down toward gas territory, at which point the sums change.

What we’d caution against is choosing a type from a running-cost table alone. Melbourne homes are mostly gas-connected, and a heat pump on the wrong wall, too close to a bedroom or with nowhere for the condensate to go, is a decision you live with for a decade.

What we see on a changeover

Most people call us on the day it fails, which is understandable and also the worst day to be choosing a system. You’re cold, the water’s cold, and somebody wants an answer in an hour.

So the thing worth knowing: a unit that’s still working can be replaced on your timetable. A hot water changeover booked a fortnight out is a different conversation from one booked at 7am in a cold shower. If yours is over ten years old and you’ve started thinking about it, that’s the moment to get a number, not the morning it gives up.

The other one is tempering valves. Plenty of older Melbourne installs either never had one or have one long past its service life, and it comes up as a surprise line on a quote. It isn’t a plumber inventing work. It’s a compliance requirement, it’s there so a tap can’t scald somebody, and it has to be right before the job passes.

How to read a hot water quote

A good hot water quote tells you the model, not just the type. “Gas storage, 170 litre” is a category. A brand and a model number is a quote you can compare against another one.

What a hot water quote should name

• The exact unit, by brand and model
• Whether removal and disposal of the old one is included
• Whether a tempering valve is included or extra
• Who handles the rebate paperwork, if a rebate applies
• The warranty on the unit and the warranty on the labour, which are two different things

If two quotes are hundreds apart, that list is usually where the difference is hiding. One of them has the valve and the disposal in it and the other one finds them on the day.