- A whole-home heat pump hydronic heating system typically costs $28,000–$55,000 installed in 2026, depending on emitters and climate.
- Heating COP of 3.5–5.5 means 1 kW of electricity becomes 3.5–5.5 kW of heat — 60–75% cheaper to run than gas, near-zero with rooftop solar PV.
- Maxa, Viessmann and Immergas each win a different brief — AHHAC carries all three, so the recommendation is independent.
A hydronic heat pump replaces the gas or electric boiler in a hydronic system, driving the same radiators, underfloor loops and fan coils with all-electric, refrigerant-cycle efficiency. Because it moves heat rather than burning fuel, it delivers far more heat than the electricity it consumes — and the same unit reverses in summer to provide silent chilled-water cooling. That dual-season, low-running-cost profile is why heat pump hydronic heating is now the default specification for new Australian builds.
What does heat pump hydronic heating cost in 2026?
For a typical 200 m² Australian home, expect the following installed ranges in 2026:
- Heat pump + hydronic underfloor (new build): $35,000–$55,000
- Heat pump + radiator retrofit: $24,000–$38,000
- Heat pump swap onto an existing hydronic system: $12,000–$22,000
Cold-climate sites (Canberra, the Blue Mountains, the Melbourne fringe) add 10–20% for larger plant and upgraded insulation. The single biggest cost driver is the emitter type — hydronic underfloor heating costs more than a radiator retrofit but delivers the most even comfort and the lowest flow temperatures (which lift heat-pump efficiency).
How to read COP (and why it decides your running cost)
COP — Coefficient of Performance — is the ratio of heat output to electricity input. A COP of 4.0 means every 1 kW of electricity becomes 4 kW of heat. Modern hydronic heat pumps run a seasonal COP of 3.5–5.5, which is roughly 4× the efficiency of direct electric heating and 60–75% cheaper to run than a gas boiler at 2026 tariffs.
COP rises as flow temperature falls, which is why pairing a heat pump with low-temperature underfloor heating (35–45 °C) beats pairing it with hot-running radiators (55–70 °C). Pair the system with rooftop solar PV and the daytime running cost approaches zero.
Running costs by climate
Climate drives the annual bill more than anything else. In mild Sydney (~700 heating degree-days) a well-sized heat pump runs at very low annual cost. Melbourne carries roughly double the load (~1,500 HDD), and Canberra nearly triple (~2,300 HDD) — so system sizing, insulation and (for the coldest sites) a hybrid backup matter far more there. Brisbane is cooling-led, so the heat pump earns its keep mostly in summer.
Maxa vs Viessmann vs Immergas — which brand?
AHHAC is authorised for all three major hydronic heat-pump makers, so we choose on merit:
- Maxa i-290 (R290): best all-in-one — heating, cooling, hot water and chilled water from one unit, highest COP (4.94), rated to −25 °C. The R32 Maxa i-32V5 is the value sibling.
- Viessmann Vitocal (R290): premium German engineering and the standout domestic-hot-water heat pump.
- Immergas Magis (R32): retrofit-friendly, with a unique heat-pump-plus-gas hybrid for cold climates.
For the full side-by-side on COP, refrigerant, output and warranty, read our Maxa vs Viessmann vs Immergas comparison.
Is it worth switching from gas?
For most homes with rooftop solar or a plan to add it, yes. A heat pump removes the gas connection (and its supply charge), cuts heating running cost by 60–75%, and adds free summer cooling on the same pipework. The hydronic distribution has a 30+ year design life — only the outdoor unit needs replacing at the 12–15 year mark. The main barriers are up-front cost and, for the coldest sites, the need for a correctly cold-rated unit or a hybrid. AHHAC will run a heat-loss calculation and give you a fixed-fee quote within 24 hours.