- Burners, furnaces, boilers, and strokers (4)
- Boilers, low-pressure heating: steam or hot water (3)
- Furnaces, domestic steam or hot water (1)
- Gas burners, industrial (1)
- Stokers, mechanical: domestic or industrial (4)
- Room and wall heaters, including radiators (1)
- Logs, gas fireplace (3)
- Room heaters, gas (2)
- Space heaters, except electric (1)
- Solar heaters and collectors (4)
- Stoves, wood and coal burning (6)
