Most Australian homes can take an all-in-one heat pump hot water system. But “most” is not “all” — and the thing that stops it is almost never what people expect. It is not the roof, the power bill or the plumbing. It is width.
This guide walks through exactly what a NeoPower All-in-One heat pump needs on site: the measurements, the slab, the power circuit, the drainage — and the two requirements that catch people out well after the quote is signed.
The Five Things That Decide It
- Clear width — roughly 1.43 m across the airflow path. This is the one that fails.
- Access to get it there — the boxed unit is taller than a standard door.
- A level concrete base rated for the weight of a full tank.
- A dedicated power circuit — not a shared one.
- Somewhere for two drains to go — relief valve and condensate.
Everything else is detail. If those five work, you are fine.
Start With the Tape Measure: 1.43 Metres
A heat pump breathes. It pulls air in one side, strips the heat out of it, and blows the now-colder air out the other. Both of those need room, and the manual sets out how much.
- Air inlet side (the left, when you are facing the unit): 200 mm
- Fan / air outlet side: 600 mm
- Above the unit, if anything overhangs it: 100 mm
The unit itself is 626 mm across on the All-in-One range, or 650 mm on the Black Shield. Add it up:
200 mm + 626 mm + 600 mm = 1,426 mm. Call it 1.43 metres of clear width — or a touch over 1.45 m for a Black Shield.
Plenty of Australian side passages are closer to a metre. That is the whole problem in one line — and it is why “we’ll just put it where the old gas unit was” so often does not survive first contact with a tape measure.
The clearances are not red tape, either. Choke the fan side and the unit starts re-breathing its own cold exhaust. Efficiency drops, the compressor works harder, and the running-cost saving you bought the thing for gets quietly eaten.
The Numbers, By Model
| Model | Tank | Unit size | Boxed size | Weight (empty) |
|---|---|---|---|---|
| NA31-210A | 210 L | Ø626 × 1,582 mm | 700 × 700 × 1,722 mm | 107 kg |
| NA32-260A | 260 L | Ø626 × 1,809 mm | 700 × 700 × 1,952 mm | 119 kg |
| NA37-315A | 315 L | Ø626 × 1,979 mm | 700 × 700 × 2,119 mm | 127 kg |
| Model | Tank | Unit size | Boxed size | Weight (empty) |
|---|---|---|---|---|
| NA43-210B | 210 L | Ø650 × 1,650 mm | Ø720 × 1,785 mm | 116 kg |
| NA44-270B | 270 L | Ø650 × 1,870 mm | Ø720 × 2,005 mm | 130 kg |
| NA45-320B | 320 L | Ø650 × 2,090 mm | Ø720 × 2,225 mm | 146 kg |
Not sure which size suits you? Our guide to choosing by household size covers that side of it.
Getting It There: The Bit Nobody Checks
Look at those boxed heights again. The 315 L All-in-One ships at 2,119 mm, and the 320 L Black Shield at 2,225 mm. A standard Australian internal door is 2,040 mm.
The box does not fit through the door. Neither do most gates with a header, or garage service doors, or the tight ninety-degree turn beside the meter box.
And you cannot simply lay it down to get it past. The compressor sits on top of the tank, and the manual is firm about this: never tilt the unit more than 45° from vertical. Go past that and the lubricating oil drains out of the compressor into the mufflers. If it does get tilted during handling, it has to stand upright for up to two hours before anyone switches it on.
At 107–146 kg empty it is also a two-person lift minimum, ideally with equipment.
So before anything else: walk the route from where the truck can park to where the unit will stand, and measure the narrowest point.
Can It Go Where My Old Gas Unit Was?
Usually yes, if there is a hard level surface, the spot has 1.43 m of clear width, the fan side faces open ground rather than a fence a foot away, and there is power nearby.
Usually not, if:
- It is a narrow side passage — the 600 mm on the fan side is the usual casualty
- The old unit sat in a boxed-in cupboard or recess
- There is an eave or awning with under 100 mm of headroom above where the unit would sit
- The fan would blow straight at a neighbour’s window or your own bedroom wall — see how loud a heat pump actually is
- There is gas at the spot but no power — running a new circuit is the single most common line item added after a site visit
If the spot genuinely will not work, that is not the end of it. A split system puts the compressor outside and the tank somewhere else entirely, and a rooftop unit sidesteps ground-level width altogether.
The Site Requirements, In Plain English
The base
A concrete plinth or equally solid structure rated to carry over 470 kg — that is the unit plus a full tank of water. Concrete at least 50 mm thick; if you are using pavers they need to be at least 600 × 600 mm. The surface has to sit within 2° of level, and all four feet must be supported. Installing it on a tilt of more than 3° can void the warranty, because condensate stops draining properly.
The power
A dedicated circuit on a 10 A breaker, protected by a type B RCBO with 30 mA leakage protection, wired in 2.5 mm². Not shared with the shed, not on the same run as the pool pump. The manual recommends hard-wiring to a 10 A isolator switch rather than relying on a three-pin plug.
The water pressure
This is where a lot of avoidable grief starts. The system is built for mains pressure up to 550 kPa, with a minimum of 200 kPa to work properly. If your mains can exceed 550 kPa at any point — and in plenty of Australian suburbs it does, especially overnight — a 500 kPa pressure limiting valve to AS1357 must be fitted.
Skip it and the classic symptom shows up within weeks: the relief valve drips constantly. People assume the valve is faulty. Usually the valve is doing exactly its job, and nothing is limiting the incoming pressure.
In Western Australia and South Australia a 700 kPa expansion control valve is required by local regulation. Elsewhere it is recommended in scale-prone areas.
The drains — both of them
An 850 kPa / 99°C relief valve comes with the system and needs a compliant discharge point. Separately, the unit produces condensate whenever it runs — that is what pulling heat out of air does — and it drains through a half-inch brass elbow into PVC. It needs constant fall, no kinks, and an air gap. Not onto the lawn or a garden bed.
The tempering valve
Mandatory. The tank stores water well above a safe delivery temperature, and the manual is blunt about why: scalding occurs at 50°C. The tempering valve mixes it down before it reaches your taps.
All of it is governed by AS/NZS 3500.4 for the plumbing and AS/NZS 3000 for the wiring, which is the short answer to “can I do this myself” — no, and doing so voids the warranty.
Installing Indoors or in a Garage
These units are designed for outdoors. Indoors is possible, but the bar is higher than people expect:
- Room volume of at least 45 m³ per unit
- Ventilation of at least 280 L/s per unit
- No ignition sources, no corrosive atmosphere
45 m³ is roughly a 4.3 m × 4.3 m room with a standard ceiling. A single garage usually clears it. A laundry, a store room or a cupboard does not.
The reason is the refrigerant. These systems use R290, which has a global warming potential of 3 against 1,430 for the older synthetics it replaced — genuinely better for the environment. The trade-off is that R290 is propane, and it is flammable. The room volume requirement exists so that a leak can never reach a dangerous concentration. It is a real constraint, not a formality.
The Requirement Nobody Mentions: Your Water
This one is buried in the warranty conditions and almost never comes up at quote stage. Your water has to meet quality limits, or the tank warranty does not apply:
| Measure | Limit |
|---|---|
| Total dissolved solids | under 600 mg/L |
| Total hardness (CaCO₃) | under 200 mg/L |
| Chloride | under 300 mg/L |
| pH | 6.5 – 8.5 |
| Magnesium | under 10 mg/L |
| Sodium | under 150 mg/L |
| Iron | under 1 mg/L |
And the blunt version: unfiltered bore, dam or river water is not covered, full stop. If you are on tank or bore water, get it tested before you buy, not after. Where dissolved solids run above 600 ppm the manual also shortens safety valve replacement from five years to three.
Hard water is survivable with the right tank. Our piece on vitreous enamel tanks and hard water goes into what actually happens inside the cylinder.
What Install Day Looks Like
A licensed plumber does the water side; a licensed electrician does the circuit if a new one is needed. Roughly, in order: water and power off, old unit disconnected and removed, base checked or poured, unit positioned with all four feet supported, plumbing and electrical connected, tempering valve fitted, tank filled and air bled through a tap, relief valve operated to purge the last of it, every joint checked for leaks, then power on and a walk-through of the controller.
If the unit was tilted at any point getting it into position, it stands upright for up to two hours before that first switch-on.
Replacing gas? The old system needs proper decommissioning by someone licensed for gas work. Victoria has its own timeline on this — see our guide to the 2027 Victorian changes.
What Can Add to the Quote
None of these are hidden fees. They are site conditions, and a good installer will flag them before starting:
- Running a new dedicated circuit from the switchboard — the most common one by a distance
- Pouring a new concrete base where there is only soil or lawn
- Extra pipework if the unit has to move away from the old location
- Fitting a pressure limiting valve or expansion control valve
- Fitting a tempering valve where none exists
- Removing and decommissioning the old gas system
- Manual handling where a trolley cannot reach
- Safe access equipment for awkward sites — the manual puts this cost on the owner
Before You Call: An Eight-Question Site Check
Answer these and we can quote accurately without a site visit in most cases. It takes about five minutes and a tape measure.
- What is there now — gas or electric, and what size?
- At the spot you have in mind, how much clear width is there across the airflow path? (You are looking for 1.43 m.)
- Is there anything overhead — eave, awning, pergola — and how much room above the unit?
- From where a truck can park to that spot, what is the narrowest doorway, gate or turn?
- Is the ground concrete, pavers, or soil?
- Is there a power point or switchboard nearby?
- How many people in the house, and how many bathrooms?
- Is the property on mains water, or tank or bore water?
Send those eight answers through and you will get a real number back, not a range.
Frequently Asked Questions
How much space does a heat pump hot water system need?
About 1.43 m of clear width, or a little over 1.45 m for a Black Shield. The unit is 626 mm across on the All-in-One range and 650 mm on the Black Shield, and it needs 200 mm on the air inlet side and 600 mm on the fan side, plus 100 mm above it if anything overhangs. Heights run from 1,582 mm up to 2,090 mm depending on model.
Can I put a heat pump where my gas hot water system is now?
Often yes, but check the width first. Gas units are compact and frequently sit in narrow side passages that cannot give a heat pump its 600 mm on the fan side. The other common blocker is that the spot has gas but no power.
Can a heat pump be installed indoors or in a garage?
Yes, if the room is at least 45 m³ with ventilation of 280 L/s or better and no ignition sources. A single garage usually qualifies; a laundry or cupboard does not. The requirement comes from the R290 refrigerant, which is flammable.
Do I need a new electrical circuit?
You need a dedicated circuit on a 10 A breaker with a type B RCBO. If the old location only had gas, or the nearest circuit is shared, a new run from the switchboard is required. This is the most common addition to a quote.
Why does the relief valve drip constantly?
Almost always because nothing is limiting the incoming mains pressure. The system is rated to 550 kPa; above that a 500 kPa pressure limiting valve compliant with AS1357 is required. Some discharge during a heating cycle is normal — constant dripping is not.
Will bore or tank water void the warranty?
Unfiltered bore, dam or river water is not covered. Filtered supply can be, provided it stays inside the published limits — total dissolved solids under 600 mg/L, hardness under 200 mg/L, pH between 6.5 and 8.5. Get a water test before you buy.
Can I install it myself?
No. The plumbing must comply with AS/NZS 3500.4 and the wiring with AS/NZS 3000, both requiring licensed trades, and R290 refrigerant must only be handled by a technician holding a refrigeration licence. Installation by an unlicensed person voids the warranty.
Still not sure whether your site will work? Send through the eight answers above, or call us on 1300 062 788 and we will talk it through. If you are in Victoria, it is also worth checking what you can claim on our Victorian rebate guide before you commit.