Reverse-cycle: the easiest to leave on
Reverse-cycle units are built to run for long periods, and an inverter unit slows down rather than switching off once the room is warm. Set a modest temperature or use the sleep mode, which eases the set point down through the night. The Victorian Government suggests 18°C to 20°C for heating living areas and says each extra degree adds around 10% to running costs; bedrooms can usually sit lower. A timer that brings the heat back on before you get up often beats running it all night.
Gas ducted heating
A flued gas ducted heater sends its combustion gases outside, and plenty of households run one overnight on a low setting or a timer. That's reasonable when it's serviced. Energy Safe Victoria recommends servicing gas heaters at least every two years by a qualified gasfitter, including a carbon monoxide test. It also warns that running rangehoods or bathroom exhaust fans while a gas heater is on can draw carbon monoxide into living spaces.
A carbon monoxide alarm is a sensible backup, but Energy Safe Victoria says it should never replace regular servicing.
Heaters to switch off before you sleep
Open-flued gas space heaters take their air from the room, and Energy Safe Victoria says they can spill carbon monoxide more easily than other types. Don't leave one running while people sleep, especially in a sealed-up room. Never bring an outdoor gas heater or barbecue inside.
Portable electric heaters need someone awake to keep an eye on them. Bedding slips, clothes get draped over them, and power boards heat up under a long, heavy load. Switch them off before bed, and follow the manual for electric blankets, most of which are meant to warm the bed and then be turned down or off.
What you can safely do now
- Use a timer or sleep mode instead of running the heating flat out all night.
- Keep rangehoods and bathroom exhaust fans off while a gas heater runs.
- Test carbon monoxide and smoke alarms before winter.
- Switch portable heaters off before bed and keep them well clear of curtains and bedding.
Services that can help
Read more in our guides
- Winter electrical safety: heaters, electric blankets and power boardsThe cold-weather risks from portable heaters, electric blankets, overloaded power boards and damp, plus safer ways to warm a room on cold July nights.
- Carbon monoxide and gas heating: what every household should knowWhere carbon monoxide comes from with gas heating, the symptoms, why exhaust fans and draught sealing can raise the risk, and what servicing and alarms do.
Related questions
- Why does my reverse-cycle heat the ceiling and leave my feet cold?Warm air rises, so a high-wall unit blowing gently forward can leave a warm layer at the ceiling and cool air at floor level.
- Why does my electric heater trip the safety switch?A safety switch trips when it detects electricity leaking to earth, and portable heaters are a common cause.
- Is my old electric blanket safe to use?Possibly, but check it before each winter.
- My rental has no fixed heater in the living area. Is that allowed?No.
Sources for this answer
2 sources, with the date each was checked
- 1.Solar Victoria (updated 20 November 2025): To heat a room, try setting the temperature between 18°C to 20°C. Every 1°C higher will add around 10% to your heating bill. Set your air conditioner thermostat for cooling between 24°C and 26°C for living areas – every… Accessed 30 September 2026.
- 2.Energy Safe Victoria: To avoid the risk, we recommend that all gas heaters are serviced at least every two years by a qualified gasfitter. A qualified gasfitter will inspect your heater and check its installation, including testing for CO… Accessed 30 September 2026.
General information for homes in Victoria. Every installation is different, so treat this as a starting point. Where this answer refers to Victorian safety or rental rules, the sources above have the current requirements.