Gas hot water out. Efficient electric in.
Hot water is the single biggest gas load in most Melbourne homes, and it is the first thing worth electrifying. We supply and install heat pump hot water systems from Daikin, Rinnai and Panasonic, decommission the old gas unit, and apply your Victorian Energy Upgrades discount straight to the invoice.
The easiest place to get off gas
Water heating accounts for roughly a fifth to a third of household energy use, and a gas storage unit is the least efficient way to do it. A heat pump does not make heat — it moves it, pulling warmth out of the surrounding air and transferring it into the tank. That is why a good unit returns several units of heat for every unit of electricity it draws.
Unlike getting off gas ducted heating, a hot water changeover does not touch your ductwork, your floor plan or your walls. In most homes it is a one-day job in the same spot the old unit stood.
And unlike your heater or cooktop, hot water is the one appliance Victoria has actually legislated. You can keep a working gas unit for as long as it keeps working — but when it goes, the replacement has to be electric.
Two ways to build it
Every heat pump hot water system is one of two shapes. The right one depends on where the unit has to go, how much hot water you use, and how cold the spot gets.
Compressor sits on top of the tank
- One unit, one footprint — the simplest swap where the old gas tank already stood
- Lower installed cost and fewer connections
- Electric boost element inside the tank for peak demand and cold snaps
- Smaller capacities available for units, townhouses and tight side passages
- Best where the site is sheltered and demand is moderate
Compressor outside, tank where it suits
- Tank can go where the old one was while the compressor goes somewhere quieter
- Higher efficiency and faster recovery, particularly on cold mornings
- Wider operating range — the CO₂ units keep working well below zero
- Larger tank capacities for big households and high demand
- Best where you want performance, quiet, or flexible positioning
Daikin, Rinnai and Panasonic
We are Daikin Hot Water Specialists and dealers for Rinnai and Panasonic — so the recommendation comes down to your site and your household, not to whatever one brand we happen to stock.
Daikin CO₂ Heat Pump
The efficiency benchmark of the three. It runs on R744 — carbon dioxide — a natural refrigerant with a global warming potential of 1, and holds its performance in genuinely cold conditions rather than falling back on the element.
- Split system: outdoor compressor, separate tank
- 250L and 315L duplex stainless steel tanks
- Nominal COP of 6.15 — among the highest rated in Australia
- Natural CO₂ (R744) refrigerant, GWP of 1
- Lead-free componentry, anti-corrosion coated condenser
- Boost mode for extra guests, optional Wi-Fi control
Rinnai Enviroflo
The broadest all-in-one line-up we install, and the practical answer for most straightforward changeovers. Every model carries an electric boost element as standard and is solar PV compatible.
- Enviroflo GR Series: integrated, 180L to 300L
- Enviroflo AR Series: integrated, 300L and 340L
- Enviroflo S: 7.0kW split, 250L / 315L / 400L
- R290 refrigerant, low global warming potential
- Electric boost element standard across the range
- Solar PV compatible, rated to 1000 kPa mains pressure
Panasonic CO₂ Heat Pump
Built in Japan, where Panasonic has led the category for more than two decades. Two outdoor capacities and a wide spread of tanks make it the most configurable option for awkward sites.
- Split system with plug-in outdoor unit connection
- 4.0kW and 6.0kW outdoor units, made in Japan
- 250L / 315L / 400L tanks, enamel or stainless steel
- COP of 6.1 on the 6.0kW model
- Operates from −10°C to +44°C
- Rated at 37dB — one of the quietest available
Sizing it properly
An undersized heat pump runs its electric element to keep up, which throws away the efficiency you paid for. An oversized one costs more than it needs to. These are the ranges we start from before we look at your actual usage.
160L – 250L
An integrated unit is usually all you need. Watch clearance around the side passage.
250L – 280L
The most common changeover size. Both shapes work well here.
280L – 315L
Worth pricing a split if you have back-to-back morning showers.
315L – 400L
Split system territory. Recovery rate matters more than raw tank size.
A guide only. We size on real usage, tank position, mains pressure and how cold the install location gets — then quote a fixed price.
Victorian Energy Upgrades discount
Replacing an eligible gas or electric resistance hot water system with an approved heat pump creates Victorian energy efficiency certificates. Our group is the accredited provider (no. A2067), so there is no middleman — we check eligibility, install, handle the certificates, and the discount comes off your invoice.
Federal STCs
Heat pump hot water systems create small-scale technology certificates under the Commonwealth Small-scale Renewable Energy Scheme. The value is already deducted from the price we quote you.
Solar Homes hot water rebate
Eligible Victorian owner-occupiers may also access a Solar Homes hot water rebate of up to $1,000, or up to $1,400 where an eligible locally made product is installed. It is a separate Solar Victoria program with its own conditions — including an income threshold and an existing system at least three years old. Ask us and we will tell you straight whether your job qualifies.
A gas-to-electric changeover, done properly
A heat pump is a plumbing job, an electrical job and a gas decommissioning job at once. Doing one of the three badly is how these installations go wrong.
- Free site assessment and fixed-price quote
- Eligibility checked before you commit
- Safe decommissioning and capping of the old gas unit by licensed gas fitters
- Removal and disposal of the old system
- Positioning for airflow, noise and clearances
- Condensate drainage run to an approved point
- Tempering valve and relief line to Plumbing Code requirements
- Dedicated electrical supply and isolation by a licensed electrician
- Solar PV or off-peak timer set-up where it suits your tariff
- Commissioning, warranty registration and a handover that makes sense
From quote to hot water in 4 steps
Tell us what you have
Call, enquire online, or drop into the Huntingdale showroom. A photo of your existing unit and its data plate covers most of what we need.
Site check and fixed quote
We confirm position, capacity, electrical supply and drainage, apply the discounts you qualify for, and quote a fixed price in writing.
Installation day
Old unit decommissioned and removed, new system installed, plumbed, wired and commissioned. Most changeovers are done inside a day.
Looked after afterwards
Warranty registered on your behalf, then serviced and supported by Accel Air — the same group that installed it.
Hot water questions, answered
Do I have to replace my gas hot water system now?
No. A working gas system can stay as long as it keeps working, and repairs are still allowed. The rule that changes on 1 March 2027 applies when an existing home's gas hot water system reaches end of life and cannot be repaired — from that point the replacement must be an efficient electric alternative. The practical argument for going early is that you choose the system and the timing, rather than deciding on the day you have no hot water. Separately, new homes built in Victoria from 1 January 2027 must be all-electric.
Will a heat pump cope with a Melbourne winter?
Yes. These units are rated well below Melbourne's coldest mornings — the Panasonic CO₂ range operates down to −10°C, and the Daikin CO₂ system further again. The integrated models also carry an electric boost element as backup. What matters more than the weather is sizing and positioning: a unit squeezed into a spot with no airflow will underperform on a mild day.
All-in-one or split — which should I get?
All-in-one is the simpler, cheaper swap and suits most sheltered sites with moderate demand. A split is worth it when you want the tank in one place and the compressor somewhere quieter, when the household is large, or when the install location is cold and exposed. We quote both where it is a genuine line call, on real numbers.
How long does the changeover take?
A straightforward like-for-like changeover is usually completed within a day, including decommissioning and removing the old unit. If the electrical supply needs upgrading or the tank is moving position, allow longer — we confirm that at the assessment, before you get the fixed price.
What happens to my gas connection?
The hot water unit is isolated and capped by our licensed gas fitters. If gas is still feeding a heater or cooktop, the connection stays live for those. If hot water was the last gas appliance in the house, you can look at abolishing the connection entirely and dropping the supply charge — worth asking about, because it is often the largest remaining saving.
Can I run it off my solar?
Yes, and it is one of the better uses of a solar system. All three ranges can be set to heat during daylight hours so the tank is charged on your own generation rather than imported power. We set the timer or PV control to suit your system and tariff at commissioning.
How much will it actually save me?
It depends on your household, your tariff and what you are replacing, so we will not quote you a number off a brochure. What we will do is show you the running cost comparison for the specific system we are recommending against what you have now, so you can make the call on real figures.
Who services it afterwards?
Accel Air, our service division — the same group, factory-trained technicians, genuine parts. Installation, warranty and servicing all sit under one roof, so there is nobody to pass the buck to.
⚡ VEU Rebate Upgrades
How the Victorian Energy Upgrades program works, and what we can apply it to.
🏠 Ducted Refrigerated Heating & Cooling
Whole-home reverse-cycle ducted systems — one discreet system for heating in winter and cooling in summer.
🔧 Service & Repairs
Breakdown repairs and preventative servicing for heating and cooling systems of all major brands.
Heat Pump Hot Water: All-in-One vs Split CO2
Hot water is the easiest part of a home to electrify. The real decision is all-in-one or split CO2 — they suit very different sites. A plain comparison.
Ready to get off gas hot water?
A free assessment, a fixed price with your discounts already applied, and installation by our own licensed team. Do it once, do it right — do it with A-Temp Installations.
Get My Free Quote*Discounts on eligible high-efficiency upgrades are available under the Victorian Energy Upgrades (VEU) program, an initiative of the Victorian Government administered by the Essential Services Commission, and are delivered by Accel Service Group Pty Ltd (ABN 23 638 362 964) as an accredited provider under the VEU program, accreditation no. A2067. Discounts are subject to eligibility and site assessment, vary with your premises, existing equipment, the product installed and certificate prices, and may change or be withdrawn without notice. In exchange for the discount, the Victorian energy efficiency certificates (VEECs) created by your upgrade are assigned to Accel Service Group Pty Ltd as the accredited provider. Accel Service Group Pty Ltd is not a government agency.
Small-scale technology certificate (STC) values are set by the Commonwealth Small-scale Renewable Energy Scheme and fluctuate with the market. The Solar Homes hot water rebate is administered by Solar Victoria and is subject to its own eligibility criteria, funding availability and program rules; amounts stated are maximums and may change. Product specifications, capacities and efficiency figures are as published by the manufacturers and are subject to change — confirm current specifications and warranty terms on your quote. Efficiency and running cost outcomes vary with household usage, water temperatures, tariff and installation conditions. Information about Victorian building and plumbing regulations is provided as a general guide only and is not legal or compliance advice.