- Burners, furnaces, boilers, and strokers (2)
- Boilers, low-pressure heating: steam or hot water (2)
- Furnaces, domestic steam or hot water (2)
- Gas burners, domestic (1)
- Gas burners, industrial (1)
- Oil burners, domestic or industrial (1)
- Stokers, mechanical: domestic or industrial (2)
- Logs, gas fireplace (1)
- Space heaters, except electric (2)
- Heaters, swimming pool: oil or gas (1)
- Steam heating apparatus (1)
- Stoves, wood and coal burning (3)
