- Burners, furnaces, boilers, and strokers (4)
- Boilers, low-pressure heating: steam or hot water (2)
- Furnaces, domestic steam or hot water (1)
- Room and wall heaters, including radiators (1)
- Logs, gas fireplace (1)
- Unit heaters, domestic (1)
- Gas infrared heating units (1)
- Solar heaters and collectors (2)
- Stoves, wood and coal burning (6)
