Heat pump installation in Nelson
Your installer will work out how fast your house actually loses heat rather than reading it off the floor plan, so the place is warm when you get up on a frosty morning instead of still catching up at breakfast.
What it costs
These are fitted prices, covering the indoor and outdoor units, the brackets and mounts, the pipework and cabling, the electrical work and the labour. What lifts one quote above another is the capacity the room needs, how far the pipework travels, and whether the switchboard has room for a new circuit.
| Type | Supplied & fitted | Suits |
|---|---|---|
| High-wall bedroom or small room | $2,000 to $2,900 | Around 2.5kW, and the cheapest way to get one room warm. |
| High-wall main living area | $2,900 to $4,400 | A 5 to 6kW unit, and what most Nelson houses end up booking. |
| High-wall large or open-plan | $3,800 to $5,500 | A 7 to 8kW unit for a big lounge or a knocked-through living and dining. |
| Multi-split two rooms or more | Quoted per head | Several indoor heads off one outdoor compressor, which keeps a bank of boxes off a tight section. Priced on how many and how far apart. |
| Ducted whole home | $12,000 to $25,000+ | Gear in the ceiling feeding vents in every room. Needs the roof space for ductwork. |
You'll get a firm price once your installer has the right measurements and details of your job. Costs can vary a lot, and the cost page goes into why.
What’s included in the price
Supply and install is handled as one job, so there's no chasing a separate supplier and sparky.
- The heat pump, sized on how fast the house loses heat
- Brackets and mounts, with the outdoor unit up off the ground
- Pipework run and lagged, and the condensate drain
- Electrical connection through a registered electrician
- Vacuum, pressure test and commissioning
- A tidy-up as the job goes, not just at the end
- Manufacturer warranty on the unit
- Removal of the old unit if there is one
How a heat pump installation works
Most single-head installs take the better part of a day.
Free quote
Tell us the rooms, your suburb, and whether the windows are original. That last one changes the capacity more than the floor area does.
Site visit
Your installer works out the heat loss rather than the square metres, finds a spot outside with airflow and away from bedroom windows, and checks the switchboard has room for the circuit.
The install
Indoor and outdoor units go up, the pipework is run and lagged, and a registered electrician wires it in. The system is vacuumed and tested before it's charged, and the wall penetration is flashed so weather stays out.
Commissioning
It gets tested and handed over properly, including how to run it on a frosty morning, which isn't the same as how to switch it on.
Which type of heat pump suits your home
A single-glazed villa in The Wood behaves nothing like a tight modern build out at Richmond, and on a still frosty morning the difference between them is bigger than the floor plans suggest.
High-wall
Mounted up high, blowing warm air across and down. The cheapest to buy and to fit, and what most Nelson rooms end up with.
Floor console
Sits low on the wall like a radiator, so the warmth lands at foot level first. On a still frosty Nelson morning, when the cold air is sitting on the floor, that's worth more than it sounds.
Ceiling cassette
Recessed into the ceiling, blowing down across a large open space. Nothing on the walls, and it needs the cavity depth above the gib.
Multi-split
Several indoor heads off one outdoor compressor, so a few rooms get heated without a bank of outdoor units down the side of a tight section.
Ducted
Gear in the ceiling feeding every room through vents. The evenest heat and the priciest, and it wants roof space to work with.
What size heat pump do you need
The size is worked out from how much heat your house loses, not from how big the room is. Those are different questions and only one of them gets you warm.
Bedroom or small room
About 2.5kW.
Living area
5 to 6kW.
Large or open-plan
7 to 8kW.
Step up from there for single glazing, a high stud, or a house with gaps you can feel.
Why the still mornings are the test
A heat pump pulls its warmth out of the air outside, so the colder that air gets the less there is in it to move and the harder the unit works for the same result. A still Nelson dawn in the middle of winter is about as cold as the air gets here, and it's the moment a unit picked off a shelf rather than matched to the house falls behind.
The stillness matters twice over. With no wind to stir it, the air inside settles into layers too, cold and heavy at the floor and warmer near the ceiling. So the room can read as warm at the thermostat while your feet say otherwise, and a unit that was borderline on capacity has no margin to sort that out.
What the house does to the figure
A single-glazed villa through The Wood or Washington Valley loses heat through the windows and the gaps about as fast as a modest unit supplies it, so it wants real capacity to hold a temperature through the evening. A tighter modern place at Richmond or Stoke holds the same floor area on considerably less.
Going bigger to be safe has its own cost. An oversized unit reaches temperature in a rush and cuts out before it has taken any moisture from the air, so the room ends up warm and clammy, and it costs more to buy and to run getting there.
Run your rooms through the sizing calculator for a starting figure, then have whoever quotes it confirm it on site.
Replacing an old heat pump
Ten years or more, struggling, or throwing error codes generally means replacing beats repairing, because parts get scarce and efficiency has moved a long way. Near the water at Tahunanui or Atawhai it comes round sooner, because the salt has been working on the outdoor unit the whole time.
Plenty of a replacement can be salvaged. Brackets, pipework and cabling that are sound and the right size for the new unit stay put, and the quote drops accordingly. Pipework still holding traces of the old refrigerant has to go, because what it leaves behind shortens the life of whatever follows it.
It's also the cheapest chance you'll get to move the outdoor unit. If the old one sat where the salt reaches it, or a couple of metres off a bedroom window, moving it while the job is already open costs a fraction of what it would as a visit on its own.
Worth knowing up front: if the old one always felt slow on cold mornings rather than broken, say so before anyone quotes. That's usually a capacity problem or a placement one, and fitting the same size in the same spot buys you the same winter with a newer warranty on it.
Consent and electrical work
A standard household heat pump doesn't need building consent. The electrical work has to be done by a registered electrician, which is part of the install rather than something you arrange separately, and the refrigerant work needs an approved filler licence.
Anything structural, or a ducted system going into a major renovation, can need consent, and that usually sits under the consent the building work already has. Nelson City Council and Tasman District Council are the authorities for their own areas.
Worth raising at the site visit: body corporate or cross-lease rules if you share a title, and how close the outdoor unit would sit to a neighbour's window. Sections here aren't always generous and a low hum carries on a still night.
Looking after your heat pump
Cleaning the filters is your job and it's a two-minute one. The front panel lifts open, the filters slide out, and a rinse under the tap and a dry is all they want. Monthly through the winter. Let them clog and the unit is trying to breathe through a blanket, so it runs longer and delivers less for it.
Near the coast, give the outdoor unit a rinse with fresh water now and then as well. It clears the salt off before it works into the metal, and it's the cheapest thing you can do for the life of the unit.
Keep the back and sides of it clear either way. A hedge grown in around it, or firewood stacked against it, stops it moving air and a unit that can't breathe can't heat.
Anything beyond that wants a technician: ice that never clears, a breaker that keeps going, water where it shouldn't be, air that comes out lukewarm, or a noise the unit never used to make. The yearly service covers the charge and the electrics.
Common questions about heat pump installation
How much does heat pump installation cost in Nelson?
Fitted, about $2,000 to $2,900 for a bedroom, $2,900 to $4,400 for a main living area and $3,800 to $5,500 for something large or open-plan, with whole-home ducted from around $12,000. Inside those figures it comes down to the capacity the room needs, how far the pipework travels, and whether the switchboard has a spare circuit.
How long does the job take?
Most single-head installs take the better part of a day. If access is tight, the pipework has a long way to go, or there's more than one unit going in, it can run into a second day, and you'll be told which when you're quoted.
Why does the floor stay cold when the unit says the room is warm?
On a still frosty Nelson morning there's no wind mixing the air, so it settles into layers with the cold sitting at floor level. A high-wall puts its warmth into the top of the room and the thermostat inside it reads that warmer air, so it eases off while your feet are still cold. Running it earlier rather than harder helps, and in a high-studded villa a floor console solves it outright.
Where should the outdoor unit go?
Somewhere with good airflow, up off the ground, and easy to reach for servicing. Near the coast at Tahunanui or Atawhai, out of the worst of the salt. And away from bedroom windows, yours and the neighbour's, because it makes a low hum and sections here aren't always generous.
Do I need a unit built for coastal air?
Near the water, yes. Salt corrodes the thin aluminium fins on the outdoor unit and once they go it sheds heat poorly and costs more to run. A coastal-spec unit costs a little more and lasts considerably longer. Inland it makes no practical difference.
Can I install one myself?
You can't. The refrigerant side needs an approved filler licence and the wiring has to be signed off by a registered electrician, so doing it yourself is against the law and cancels the warranty into the bargain. Clearing the wall and agreeing where things go is the part that's yours.
Do I need consent?
Not for a standard household heat pump. Structural work or a ducted system in a major renovation can need it, and Nelson City Council or Tasman District Council is the authority depending where you are. Body corporate and cross-lease rules are worth checking before booking.
What will it add to the power bill?
Over a Nelson winter, a unit that's the right size for the room typically puts $25 to $60 a month on the bill, depending how long it runs and how much warmth the house lets go. For every unit of power it draws it moves three to four units of heat, which is the whole reason it beats a heater.
Get a price for your place
Send the rooms, your suburb and how the place is built. Your local installer will work out the heat loss properly and give you one fixed price.