There’s no single answer that applies to every home. Hydronic heating tends to run efficiently because it heats water once and holds that warmth in radiators or in-floor pipes, but your actual bill comes down to your home’s insulation, how many zones you’re heating, your energy plan, and how cold the run of weather is. Gas ducted heating can be quick to warm a whole house but loses some heat through ducting. Split systems are efficient per room but get more expensive if you’re trying to heat several rooms at once. The only reliable way to know your real number is to look at your specific home, not a generic average.
Why “which is cheaper” doesn’t have one answer
If you’ve searched for a straight dollar comparison between hydronic heating, gas ducted heating, and split systems, you’ve probably noticed nobody gives you a straight number, and there’s a reason for that. Running cost isn’t really about the system, it’s about how that system interacts with your specific home: how well insulated it is, how many rooms you’re actually heating at once, what energy plan you’re on, and how the winter behaves that year. Two identical hydronic systems in two different Geelong homes can have noticeably different running costs. So instead of chasing a single figure, it’s more useful to understand what’s actually driving the cost, then get a number based on your own home.
What actually drives your running cost
- Insulation and draught sealing. A well-insulated home holds heat, so the system doesn’t have to keep working to replace what’s escaping. This affects all three system types, but it hits ducted air systems hardest, since warm air escapes faster than radiant heat.
- How many zones you heat, and for how long. Heating your whole house all evening costs more than heating the two rooms you’re actually using. Systems that zone well (hydronic and split systems both do this room by room) give you more control here than a single-zone ducted system.
- Your energy plan and tariff. Gas and electricity pricing varies by retailer and plan, and it changes over time, so any “typical cost” quoted today may not hold next winter. This is worth checking against your own bill rather than a generic average.
- How cold the season is. A mild Geelong winter and a genuinely cold one can produce noticeably different running costs on the same system, which is part of why year-on-year comparisons from homeowners can be misleading.
Hydronic heating: where the savings and the costs come from
Hydronic heating warms water once in a boiler and circulates it through radiators or in-floor piping, so it’s not constantly reheating air that’s escaping through gaps and ductwork. That’s the main reason it’s often described as efficient to run once it’s up to temperature. The trade-off is on the install side rather than the running side: hydronic systems typically cost more to install than a comparable gas ducted or split system setup, so the running-cost efficiency is part of a longer-term picture, not necessarily the cheapest option in year one. Precision installs and services hydronic heating systems across Geelong, and for more on how the system itself works, see our guide to how hydronic heating works.
How it compares to gas ducted and split systems
| Hydronic heating | Gas ducted heating | Split system | |
|---|---|---|---|
| How it heats | Circulates hot water through radiators or in-floor pipes | Pushes heated air through ducting and vents | Heats and blows air directly into one room per unit |
| Zoning | Room by room, since each radiator/loop can usually run independently | Whole-house or zone by damper, less granular | Room by room, but you need one unit per room or area |
| Where cost tends to creep in | Higher upfront install cost | Heat lost through ducting, especially in older or roof-space ducting | Running several units at once to cover multiple rooms |
| Best suited to | Homes wanting even, room-by-room warmth without moving air | Homes with existing ducting wanting to heat the whole house at once | Homes heating one or two rooms, or wanting supplementary heating |
This isn’t a “one wins” comparison. If you’re mostly heating a couple of living areas in the evening, a split system or a well-zoned hydronic setup can both work out reasonably efficiently. If you want the whole house warm without thinking about it, gas ducted is built for that, at the cost of some heat loss through the ducting. If air quality or allergies matter in your household, that’s a separate factor worth weighing alongside running cost, not instead of it. We also install and service ducted gas heating across Geelong, and if you want a closer look at hydronic against a split system specifically, see our hydronic vs split system comparison.
Getting a real number for your home
Because insulation, zoning, your energy plan, and the season all move the number, the most useful next step isn’t another average online, it’s a proper assessment of your actual home. That’s the only way to get a running-cost estimate that reflects your house rather than a generic Geelong average.
Frequently Asked Questions (FAQs)
Is hydronic heating always cheaper to run than gas ducted heating?
Not always. It depends on your home’s insulation, how many zones you heat, and your energy plan. Hydronic tends to be efficient once it’s running, but a well-zoned gas ducted system in a well-insulated home can also run efficiently. We can talk through what your specific home would likely look like.
Why does my neighbour's heating bill look so different from mine, even with a similar system?
Insulation, draught sealing, how many rooms you heat and for how long, your energy plan, and even how the two homes are oriented can all create a real difference between otherwise similar systems. It’s rarely just about the heating type.
Trying to work out what hydronic heating, gas ducted heating, or a split system would actually cost to run in your Geelong home? Call Precision on 03 5221 0052 for an honest assessment based on your actual property, not a generic average.
