What do the panels do?
Solar Victoria describes hydronic systems as circulating water through radiator panels in each room. Each panel normally has its own valve, so you can turn one room down without touching the rest, and the ACT Government says hydronic heating can be zoned to a single room.
Adding or swapping a panel is usually a modest plumbing job, once the installer has checked the boiler can carry the extra room.
When the boiler is the problem
Signs worth a call: the pressure gauge keeps dropping, rooms won't reach temperature, the boiler locks out or gets noisy, or the flame looks different. Energy Safe Victoria says a flame that changes from its usual colour needs a qualified gasfitter to inspect it and check for carbon monoxide.
A gas boiler is a gas heating appliance, and ESV says to have gas heaters serviced at least once every two years. If it's had a proper service and still struggles, replacement belongs in the conversation.
Gas boiler or heat pump?
| Gas boiler | Heat pump | |
|---|---|---|
| Runs on | Gas | Electricity |
| How it makes heat | Burns gas to heat the water | Takes heat from the outside air and turns it into hot water, as Solar Victoria describes it |
| Outside, you'll see | A flue | An outdoor unit that needs air around it |
| Who does the work | A gasfitter, a plumber and often an electrician | A plumber and an electrician, plus an ARC-licensed technician if refrigerant pipes join two parts |
| Servicing | At least every two years, like any gas heater | As the manufacturer's manual sets out |
The rules that change the choice
From 1 January 2027, Victoria prohibits connecting mains gas to an existing building that doesn't already have it, or to one under construction. Homes with gas aren't pushed off it: DEECA says there's no requirement to move existing gas space heating to electric.
If your boiler also makes your hot water, ask one more question. From 1 March 2027, Victoria prohibits replacing a mains gas water heater with another one in an existing home, with exemptions, and those regulations have no matching rule for gas space heaters. Your gasfitter should explain how a combined unit is treated.
In NSW, the Energy Savings Scheme gives no incentive for a gas hot water boiler or space heater installed from 1 July 2026.
What makes a heat source swap bigger or smaller
A gas boiler replaced in the same spot, on the same flue, is the simplest job. Moving to a heat pump adds an outdoor unit, a power circuit and sometimes a buffer tank (a small store of hot water that smooths out the heat pump's running).
Heat pumps generally prefer cooler water than a gas boiler sends round, so the installer should check your existing panels can still heat each room. If some need upsizing, that belongs in the quote from the start, and it's where a hydronic specialist earns their keep.
Your checks, and the installer's work
You can
- Glance at the boiler's pressure gauge now and then, and note any change.
- Make sure the valves are open on panels in rooms you want warm.
- Bleed air from a panel only if your system's manual shows you how.
- Keep the space around the boiler and its flue clear.
Leave to a licensed installer
- Anything inside the boiler, its gas controls or the flue.
- Replacing pumps, valves or panels.
- Installing a heat pump, its circuit and any refrigerant pipework.
- Carbon monoxide testing on a gas boiler.
What we'd do
Our take
If the panels are fine and the boiler is old, we'd keep the panels and put our attention on the heat source. With gas already connected, a like-for-like boiler is the simpler job. If we were adding rooms, building new in Victoria or wanted off gas, we'd have a hydronic specialist check our panels against a heat pump before deciding anything.
