Gas heater vs reverse-cycle running cost.
Compare what a gas ducted heater and a reverse-cycle (heat pump) system will actually cost to run per winter. Enter your home’s heat load, the star rating of your current gas heater, the COP of the reverse-cycle system, plus your gas and electricity rates.
Home & usage
Gas heater
Reverse-cycle system
Install & rebate (for payback)
Which is cheaper to run?
By switching from a 5-star gas heater to a reverse-cycle COP 4.0 system. Payback in 11.3 years at $8,600 net install cost.
Estimate only — real running cost varies with outdoor temperature, thermostat setpoint, house insulation and how many zones are running. RC systems in Melbourne hills (Emerald, Gembrook) should use the Mitsubishi FH Hyper Heating COP (~3.8 at -5 °C), not a standard 4.0 rating.
How the calculation works
We compute the delivered heat energy needed per year — heat load (kW) × hours per day × days per year. That’s the same output both systems have to hit.
Gas heater: input MJ needed = delivered heat ÷ efficiency. A 3-star heater is ~65% efficient, 5-star ~82%, 6-star ~87%. Multiply input MJ by your gas tariff to get $/year.
Reverse-cycle: input kWh needed = delivered heat ÷ COP. A modern inverter running in mild Melbourne winter conditions averages a COP of 3.5-4.5. Multiply input kWh by your electricity tariff to get $/year.
A rough Melbourne heat load reference: small unit (1 bed) ~2-3 kW, 3-bed home ~6-10 kW, large / double-storey ~12-18 kW. Ducted systems typically run 4-8 hours/day for ~120-150 days per year.
Big picture: a modern reverse-cycle unit on 2025 tariffs typically runs at half the cost of a 3-star gas ducted heater. The VEU rebate makes the swap cost dramatically less — estimate your rebate.
Ready to price the swap?
Send us the current heater — we’ll quote the reverse-cycle upgrade with rebate applied.