How does a gas wall furnace work?
Seeley describes a wall furnace as drawing cool air in at the top, heating it in a chamber and pushing warm air out at the bottom. It pitches them at living areas.
Two things catch owners out. Seeley says a wall furnace won't run without electricity, so a blackout means no heat. And Seeley's page now says its Braemar wall furnace line has been retired, so check what's available before planning a like-for-like swap.
Flued, open-flued or unflued?
| Flued | Open-flued | Unflued | |
|---|---|---|---|
| Where the exhaust goes | Outside, through the flue | Up a flue, but it burns air from the room | Into the room |
| What the regulators say | ESV says any gas heater can spill carbon monoxide | ESV says these spill it more easily than other types | The ACT Government says replace one immediately |
| Next step | Service at least every two years | A spillage test at every service | Replace it. Better Health says any over 10 years old should go |
When should you replace rather than service?
Unflued heaters are the clearest case: the ACT Government recommends replacing one straight away because of the carbon monoxide fumes.
Energy Safe Victoria has also issued a safety alert on four open-flued models: the Regency i31, Regency F38/FG38 (excluding LP models), Nectre 2000 and Real Flame Pyrotech. Leave one of those off until a qualified gasfitter has tested it.
A heater that fails its carbon monoxide test, needs parts that can't be found, or keeps needing repairs is ready to go. In Victoria, an old open-flued model may have no straight replacement, because open-flued heaters that can't shut down automatically can no longer be sold there.
New gas heater or reverse cycle?
With gas already at the wall, a new flued heater is the familiar path. Look at the ACT Government's comparison first: a gas wall heater at 85% efficiency, an electric element heater at 100%, and reverse cycle at 370% to 600%, because a heat pump moves heat rather than making it.
If you own the home, the choice is yours: DEECA says existing Victorian homes don't have to move gas space heating to electric. Our gas to electric page and reverse cycle or gas guide go further.
What makes a replacement bigger or smaller
A new flued heater that fits the existing flue and wall opening is the simplest swap. It grows if the flue has to move, the opening changes or the gas line needs work.
Going electric means a gasfitter removes the heater and makes the gas safe, the wall is patched, and a split system goes in. Mitsubishi Electric says a split needs its own dedicated power supply, so the switchboard is part of the quote. A heating specialist who does both jobs can quote them side by side.
What you can check, and what needs a gasfitter
You can
- If a wall furnace won't start, check its power point and the switchboard first.
- Note the brand and model from the heater's plate for the gasfitter.
- Keep curtains, couches and washing well back from it.
- Stop using an unflued heater and book its replacement.
Leave to a licensed installer
- Servicing, spillage testing and work inside the heater.
- Removing an old heater and making the gas safe.
- Fitting a new heater and flue.
- New power points or circuits (a licensed electrician).
What we'd do
Our take
If it's unflued, we'd replace it now rather than pay to service it. If it's a flued wall furnace that passes its carbon monoxide test, we'd keep servicing it and plan the replacement before a cold snap forces it. Then we'd get one quote for a flued gas heater and one for a reverse cycle split, and choose with both in front of us.
