Easy Do-It-Yourself Heat Output Rating
You can ignore outrageous claims by using this simple formula (which is how the Australian Gas Association derive their figures - Energy Labelling Standard A.G.A 103).
The formula using the Star Rating to calculate overall heat output is:


Who Does The Testing?
All gas appliances are tested for performance and safety to stringent standards imposed by the
Australian Gas Association, the independent authority who certify appliances.
What Do The Results Mean?
There are four key results that define the performance and efficiency of your heater.
- Gas Input - this measures how much gas is put into your heater per hour. eg. 30Mj/h (30 megajoules per hour)
- Combustion Efficiency - this measures how much of the potential heat is extracted from the firebox into your home. eg. 92%
- Concection Efficiency - this measures the efficiency of transferring the heat from the firebox into your home. eg. 85%
- Overall (Output) Efficiency - this measures how much of the full potential heat of the gas is put into your home. ie. combustion efficiency multiplied by the convection efficiency eg. 78%+
AGA Star Ratings
| Star Rating |
Overall Ouput Efficiency |
| One Star |
49.5% |
| Two Stars |
50 to 56.9% |
| Three Stars |
57 to 63.9% |
| Four Stars |
64 to 70.9% |
| Five Stars |
71 to 77.9% |
| Six Stars |
78%+ |