In short
Hydronic heating has two parts that you choose separately: what heats the room (underfloor pipes, radiator panels or trench convectors) and what heats the water (an air-to-water heat pump, an electric boiler or a gas boiler).
The best hydronic heating system is the combination that suits your floors, walls, glazing and energy supply. New Victorian homes must be built all-electric from 1 January 2027, so in a new build the water is usually heated by a heat pump.
Key takeaways
• Hydronic heating circulates heated water through a closed loop of pipes to radiators, trench convectors or the floor.
• In-slab underfloor heating is installed during construction and, according to the Australian Government's YourHome guide, is slow to warm and cool.
• Radiators heat a room faster than a slab and are the usual way to add hydronic to an existing home.
• Trench convectors sit in the floor along glass walls, where a radiator would block the view.
• Hydronic heating can use gas, but it does not have to: a heat pump or electric boiler heats the water without it.
Hydronic heating is often misunderstood. People picture one product, when it is really a set of choices. Once you see those choices laid out, it becomes much easier to pick the right combination for your home.
What is hydronic heating?
Hydronic heating warms your home with water instead of air. A heat source heats the water, a pump circulates it through a sealed loop of pipes, and the heat comes off radiators, convectors or the floor into each room. The same water goes back to be reheated. YourHome describes hydronic systems as circulating hot water through radiator panels in rooms or under the floor.
Because nothing is blown into the room, hydronic heating is quiet and creates no draughts from vents. See how we design and install it on our hydronic heating page.
What are the main types of hydronic heating?
There are three ways the heat can come into a room. Many homes use more than one.
Underfloor heating
Pipes are laid in a loop across the floor and covered by the slab or floor build-up, so the whole floor becomes a gentle, even heat source. It suits new builds and major renovations on a slab.
The trade-offs: YourHome notes in-slab systems are installed during construction or renovation, are slow to warm and cool because of the slab's thermal mass, and are unsuitable for houses where heating is only needed occasionally. It suits households that are home a lot through winter. Read more on our underfloor hydronic heating page, and if you are getting quotes, see 7 key questions to ask when getting an underfloor heating quote.
Radiators
Panel radiators mounted on walls, each fed by a pair of pipes. Each radiator can have its own valve, so rooms can be turned up or down individually. Radiators heat a room much faster than a slab, and they are the usual way to add hydronic to an existing home as well as a new one.
The trade-offs: they take up wall space, and YourHome recommends insulating exterior walls behind the panels to stop heat escaping outside. See our hydronic radiators page.
Trench convectors
A heater set into a channel in the floor, usually along full-height glass, with a grille on top that sits flush with the floor. Warm air rises along the glass, so you get heat where homes tend to lose it without a radiator blocking the view.
The trade-off: the trench has to be planned into the floor during the build. See trench convectors.
What heats the water?
The second choice is the heat source. YourHome lists electric, solar and gas as heat sources for hydronic systems. For Melbourne homes, these are the three main options.
Air-to-water heat pump
An outdoor unit takes heat from the outside air and moves it into the water. It runs on electricity, so it fits the all-electric rules for new homes. YourHome describes heat pumps, including reverse cycle air conditioners, as the most energy-efficient combined heating and cooling system you can buy. See our air-to-water systems page.
Electric boiler
A unit that heats the water directly with electricity, with no outdoor unit. It is all-electric too. If you are heating a slab, ask how it compares with a heat pump to run: YourHome notes that electric in-slab heating generally has the highest energy use of any heating system. See boilers and thermostats.
Gas boiler
The traditional heat source, still common in existing homes with a gas connection. For new homes, Energy Victoria says electrification requirements apply to all new residential buildings from 1 January 2027, with some exemptions, so a gas boiler is off the table for most new builds. If you are upgrading an existing gas system, our hybrid heating page explains another path.
Does hydronic heating use gas?
It can, but it does not have to. The pipes, radiators and floor loops work the same whatever heats the water. A gas boiler, an electric boiler or an air-to-water heat pump can all supply the heat. In a new Victorian home from 2027, it will usually be a heat pump.
Which hydronic heating system is best?
There is no single best system. The best one is the combination of room heating and heat source that fits your home. These questions narrow it down quickly:
• Are you building new or upgrading? Building new keeps every option open, including underfloor. Upgrading usually points to radiators.
• What are your floors and glazing like? Large areas of floor-to-ceiling glass suit trench convectors. Open-plan living on a slab suits underfloor.
• How often do you heat? If someone is home most days through winter, the slow, steady warmth of underfloor suits. If heating is occasional, radiators respond faster.
• What is your energy supply? All-electric new builds need a heat pump or electric boiler; an existing home with gas has more options.
• How will you cool? Hydronic is chosen for heating, so plan cooling at the same time, often with split systems.
You can combine types too, such as underfloor heating in the living areas and radiators in the bedrooms, all running from one heat source.
How do you keep hydronic heating efficient?
Good design does most of the work. YourHome's advice for hydronic and in-slab systems:
• Insulate the water pipes, and use smart controls to manage pump use. Unnecessary circulation and poor pipe insulation are the usual causes of higher running costs.
• Insulate exterior walls behind radiator panels.
• For underfloor, insulate the slab edges, and ideally the entire slab, from the ground.
• Use heating zones and thermostats, which YourHome calls essential to reduce energy use.
On top of that, the heat source needs to be sized for the home. We work it out room by room from your plans, not from a rule of thumb.
Ducted or hydronic?
If you are still choosing between hydronic and ducted reverse cycle, the biggest differences are cooling, comfort and timing. Read our guide to ducted vs hydronic heating for a new Melbourne home.
Frequently asked questions
What are the main types of hydronic heating?
Underfloor heating, radiator panels and trench convectors. All three use heated water circulating through pipes; they differ in where the heat comes into the room.
Does hydronic heating use gas?
It can, but it does not have to. The water can be heated by a gas boiler, an electric boiler or an air-to-water heat pump. From 1 January 2027, new homes in Victoria must be built all-electric, with some exemptions.
What is the best hydronic heating system?
There is no single best system. The right one depends on whether you are building new or upgrading, your floors and glazing, how often you heat, and your energy supply. You can also combine types, such as underfloor heating in living areas and radiators in bedrooms.
Is hydronic heating efficient?
It can be, if it is well designed. YourHome notes that higher running costs are usually caused by unnecessary water circulation or poor pipe insulation, and recommends insulated pipes and smart controls. The heat source matters too.
Can I add hydronic heating to an existing home?
Yes, radiators are the usual way to add hydronic heating to an existing home, with pipes run to each room. In-slab underfloor heating is installed during building construction or a major renovation.
Your next step
Not sure which type of hydronic suits your home? Send us your plans or tell us about your current setup, and book a free assessment. We will recommend the right mix of underfloor, radiators and convectors, and the heat source to run them. Prefer to start on your own? Take the 2-minute system finder, or call 1300 139 177.
