Quick answer: Water & Gas Worx supplies and installs integrated heat pump hot water cylinders across Auckland — the most energy-efficient option with running costs of $200 to $400 per year. We install the full Rheem AmbiPower, AmbiHeat, and Rinnai Enviroflo and HydraHeat range from $6,399 incl GST. Price includes supply, installation, old unit removal, electrical connection, and warranty registration. Installed by Peter — licensed plumber. Call 0800 322 322.
Models We Supply & Install
Five integrated heat pump cylinders cover the full range from entry-level through premium. The right one for your home depends on household size, outdoor space, and how much flexibility you want over operating modes.
Rheem AmbiPower MDc-180
Compact 178L integrated heat pump with a COP of 4.5. The most affordable entry point into heat pump hot water. Rated for households up to 4 people. 48 dB(A) operation and proven Rheem reliability.
Rinnai Enviroflo 265L
R290 refrigerant (GWP 3), 46 dB(A) operation, built-in Wi-Fi and five operating modes. COP 4.1 to AS/NZS 5125. Operates −7°C to +45°C. Suits 2–5 people.
Rheem AmbiPower 280e
280L tank with class-leading COP of 5.2 at 19°C, climbing to 6.7 in summer. Uses R290 ultra-low GWP refrigerant and microchannel heating. Rated for up to 6 people — the largest capacity in our heat pump range. 47 dB(A).
Rinnai HydraHeat 275L
Highest COP in the range (4.7 to AS/NZS 5125) and the widest heat pump window — full heat pump mode down to −10°C. R290, OLED control, six modes (Standard / Boost / Eco 55 / Eco 50 / High Usage / Element Only). Head unit built in NZ. Suits 2–5 people.
Rheem AmbiHeat HDc-270
Rheem's Platinum series flagship — interactive LED touchscreen, wraparound microchannel heat exchangers and R513a refrigerant. COP 4.4 at 19°C, operates −5°C to +43°C. Suits up to 6 people.
The Integrated Heat Pump Range
An integrated heat pump hot water cylinder uses the same principle as a reverse-cycle air conditioner — it pulls heat out of the outdoor air and transfers it into the water inside the cylinder. The compressor, fan and tank all live in a single outdoor unit, which means no indoor cylinder, no refrigerant lines to run, and no separate components to install or maintain. In Auckland's mild climate, this is the most efficient way to heat water year-round.
We supply and install the full Rheem and Rinnai integrated heat pump range across Auckland — from the compact 180L Rheem AmbiPower MDc-180 for smaller households through to the premium 275L Rinnai HydraHeat with six operating modes. Every installation includes removal of the old cylinder, plumbing and electrical connection, condensate drain, and full warranty registration with the manufacturer.
How a Heat Pump Hot Water Cylinder Works
A heat pump does not generate heat the way an electric element does — it moves heat. A fan pulls outdoor air across a refrigerant-filled coil. The refrigerant absorbs heat from the air, gets compressed (which raises its temperature further), then transfers that heat into the water inside the cylinder. The cooled refrigerant cycles back and repeats. This is the same process your fridge uses in reverse.
Because the unit is moving existing heat rather than creating it from scratch, it produces 3 to 4 units of heat for every 1 unit of electricity consumed. That ratio is the COP (coefficient of performance), and it is why heat pumps run on roughly a third of the electricity of a standard cylinder.
Running Cost Comparison — Auckland 2026
Based on a 3-bedroom Auckland home with average hot water usage:
- Standard electric cylinder — $800 to $1,200 per year
- Gas continuous flow — $600 to $900 per year
- Gas storage cylinder — $700 to $1,000 per year
- Integrated heat pump — $200 to $400 per year
Over a 15-year lifespan, a heat pump saves $6,000 to $12,000 on electricity versus a standard cylinder. Most households see payback in 4 to 7 years.
Which Size Do I Need?
- Up to 4 people — Rheem AmbiPower MDc-180 (178L). Compact footprint with COP 4.5, ideal for smaller households and first homes.
- Up to 5–6 people — Rinnai Enviroflo 265L (COP 4.1, 46 dB(A), built-in Wi-Fi) or Rheem AmbiPower 280e (R290 microchannel, COP 5.2 at 19°C, up to 6 people). Both run R290 refrigerant with a GWP of just 3.
- Up to 5–6 people, premium controls — Rinnai HydraHeat 275L (COP 4.7, OLED controller, R290, NZ-built head unit, heat pump mode to −10°C) or Rheem AmbiHeat HDc-270 (COP 4.4, LED touchscreen, R513a, wraparound microchannel). Both $8,299 installed.
- 5+ people or very high usage — Talk to us about twin-cylinder setups or a larger split system.
Installation — What's Included
Every heat pump hot water cylinder installation from Water & Gas Worx includes:
- Full supply of the new heat pump unit
- Removing and disposing of your old cylinder
- Positioning the new unit outdoors on a prepared concrete pad or stand
- Connecting hot and cold water lines with lead-free combi valve pack
- Dedicated outdoor electrical switch and connection
- Condensate drain installation
- Filling, testing and commissioning the unit
- Registering the manufacturer warranty on your behalf
- Certification in line with PGDB requirements
Most installations are completed in a single day. If you are replacing a failed electric cylinder, the existing hot and cold water connections are already in place — the main work is positioning the new outdoor unit, connecting the plumbing, and running the dedicated electrical circuit.
Why Choose a Heat Pump?
- Lower running costs — 60–75% cheaper to run than a standard electric cylinder.
- Simple installation — integrated units are a single outdoor box. No separate tank, no refrigerant lines.
- Future-proof — New Zealand is moving away from gas. Heat pump hot water is the leading long-term alternative.
- Backup element — every unit has an electric element as backup for extreme demand or cold snaps.
- Frees indoor space — the unit lives outside, giving you back the cupboard your old cylinder occupied.
- Quiet operation — 37–50 dBa, similar to a quiet conversation.
For the full heat pump range and pricing, visit wgw.co.nz/hot-water/cylinders/heat-pump
Frequently Asked Questions
How much does a heat pump hot water system cost in Auckland?
Integrated heat pump hot water cylinders start from $6,399 incl GST fully installed. The Rheem AmbiPower MDc-180 at $6,399 is the entry point. Mid-range units (Rinnai Enviroflo 265L, Rheem AmbiPower 280e) are $7,499 installed. Premium tier (Rinnai HydraHeat 275L, Rheem AmbiHeat HDc-270) is $8,299 installed. All prices include supply, install, old cylinder removal, plumbing, electrical connection and warranty registration.
How much will I save on power bills with a heat pump?
Heat pump hot water cylinders use up to 75% less electricity than a standard electric cylinder. A typical three to four person Auckland household will spend $200 to $400 per year on hot water, versus $800 to $1,200 on an electric cylinder. That is annual savings of $400 to $800, or $6,000 to $12,000 over a 15-year lifespan.
Is a heat pump hot water cylinder noisy?
Modern integrated heat pumps run at 46 to 56 decibels depending on the model. The Rheem AmbiHeat HDc-270 is the quietest in the range at 47 dB(A), closely followed by the Rinnai Enviroflo GR Series at 46 dB(A) — Rinnai positions it as quieter than an average household dishwasher. Most neighbours do not notice them once installed.
Does a heat pump work in Auckland winters?
Yes. Every unit we install operates efficiently across Auckland's winter range. The Rinnai HydraHeat has the widest window — full heat pump mode right down to −10°C — and the Rheem AmbiHeat HDc-270 runs from −5°C to +43°C. Auckland winter lows rarely drop below 5°C, so every unit in the range runs at full efficiency year-round.
Which heat pump is best for my household?
For 1 to 4 people, the Rheem AmbiPower MDc-180 (178L, $6,399) is excellent value. For households up to 6 people, either the Rinnai Enviroflo 265L or Rheem AmbiPower 280e at $7,499. For premium controls, LED touchscreen and six operating modes, choose the Rinnai HydraHeat 275L or Rheem AmbiHeat HDc-270 at $8,299 — both rated for up to 6 people.
How long does heat pump installation take?
A standard heat pump hot water installation takes one full day. This includes removing your old cylinder, positioning the new unit, connecting plumbing and electrics, installing the condensate drain, testing, and registering the warranty. You have hot water again by that evening.
Can I replace my electric cylinder with a heat pump?
Yes. We remove your old electric cylinder and install the new heat pump outdoors. The indoor space your old cylinder occupied is freed up. The heat pump connects to your existing hot water plumbing — no major modifications needed in most cases.
What is the payback period for a heat pump?
Most Auckland households see a payback period of 4 to 7 years. After that, you save $400 to $800 every year for the remaining 10 to 15 years of the unit's life. The higher your hot water usage, the faster the payback.
