1. The heat transfer process in which warm air rises and cool air falls represents _____.

2. The body loses heat less rapidly when the humidity is _____.

3. In order for combustion to occur, there must be _____.

4. Incomplete combustion generally results from _____.

5. If an induced-draft gas burner produces a flame that is completely blue, or blue with slight yellow tips, it is an indicator of _____.

6. Which furnace configuration does a multipoise furnace most closely match as delivered from the factory?

7. The burner gas input rate can be varied in 1 percent increments by using _____.

8. Which of these conditions will cause the flame to lift off the burner surface?

9. Flame rectification is used for pilot safety on _____.

10. The high-temperature limit switch mounted above or beside the heat exchanger of a gas furnace should cycle open if _____.

11. It is acceptable to vent a gas appliance through a masonry chimney as long as _____.

12. Soot appearing on the burners and heat exchangers could indicate a _____.

13. The boiler system component that monitors water temperature and typically controls the burner of a standard boiler is _____.

14. The typical power supply for a residential electric furnace is _____.

15. When the outdoor temperature falls below the balance point, an air-to-air heat pump _____