Underfloor heating + hot water · Auckland
DuoHeat: underfloor heating and hot water from one heat pump
One DuoHeat unit · two everyday jobs
A DuoHeat heat pump runs your hydronic underfloor heating and your household hot water from a single machine — fewer units to buy, site and service, and the same free heat from the air doing both jobs.
Why DuoHeat
One heat pump, warm floors and hot water
A DuoHeat heat pump does two jobs from one outdoor unit. It warms your floors through the pipes in the slab, and whenever the hot water cylinder needs topping up it switches across, heats the cylinder, then goes straight back to the floor. That means one unit to buy, install and service instead of a heat pump plus a separate hot water system, only one unit taking up space outside, and one power supply. Your hot water is heated by the heat pump too, using up to 75% less energy than an ordinary electric element, all year round.
The cylinder can go INSIDE or OUTSIDE
We can fit the hot water cylinder inside the property or outside, right beside the heat pump, so there is no need to find a cupboard or space inside the house for it. On this job the DuoHeat unit on the left heats the underfloor and the outdoor cylinder next to it, with short, insulated pipe runs between the two.
How the system works
Swipe the diagram sideways to follow the full circuit →
Free heat from the air
The Heatpump unit pulls warmth from the air and lifts it to a comfortable water temperature.
Balanced at the manifold
Flow and return pipes feed every floor loop from a cabinet tucked away in a storage cupboard.
Hot water supply
The same heatpump charges a hot water cylinder through an internal coil, ready for showers and taps.
Floors and pool from one system
A single heatpump keeps the floors warm and the hot water flowing, all from the air outside.
The heat pumps
DuoHeat underfloor + hot water units
Five NZ-made units, from a small home to a large one. Click a unit to see its full specifications and download the spec sheet.
7GU5D4-15 kW floor · 4 kW hot waterSingle phaseSpecs →
7GU18D15-318 kW floor · 15 kW hot waterThree phaseSpecs →
7GUb18D15-318 kW floor · 15 kW hot waterThree phase · buffer tank + pump built inSpecs →
7GU24D18-324 kW floor · 18 kW hot waterThree phaseSpecs →
7GUb24D18-324 kW floor · 18 kW hot waterThree phase · buffer tank + pump built inSpecs →Questions
What people ask us
Can one heat pump do the floors and all our hot water?
Yes — that’s the DuoHeat idea. Underfloor heating and stored hot water are both low-and-steady loads, so a single well-sized heat pump handles both, with controls sharing it between them. It saves buying, siting and servicing two separate machines.
Will we still have enough hot water?
As long as the cylinder is sized for your household, yes. A heat pump heats the cylinder slowly, so it relies on stored hot water rather than fast reheating. We size the cylinder at quote stage, and a backup element covers the busiest days.
Is it better than a separate underfloor unit and a hot-water unit?
For most homes, yes — one unit means one install, one power supply, one service visit and less plant-room space. Where the two loads are unusually large we may split them; we’ll tell you which suits your home.
Does the underfloor still work while it’s making hot water?
The controls prioritise between the two — usually a short hot-water top-up, then back to the floors. Because a slab holds its warmth, brief switches to hot water aren’t something you feel underfoot.
Free, no obligation
Request a quote
Tell us about your home — floor area, how many of you, and how you heat water now — and we’ll size a DuoHeat system that covers both.