- Burners, furnaces, boilers, and strokers (4)
- Boilers, low-pressure heating: steam or hot water (1)
- Furnaces, domestic steam or hot water (2)
- Gas-oil burners, combination (1)
- Oil burners, domestic or industrial (2)
- Space heaters, except electric (1)
- Steam heating apparatus (1)
- Stoves, wood and coal burning (5)
