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