Combustion Safety Quiz

1. Question

Which of these tests is the most direct verification that backdrafting is or isn’t happening?

Spillage test.
Draft test.
CO test.
Steady-state efficiency test.

2. Question

What is the most important thing to verify during worst-case combustion appliance zone (CAZ) testing?

That combustion gases exit the home up the chimney.
That combustion-air openings are not plugged.
That the CAZ contains no negative pressure.
That dilution air is adequate to prevent CO.

3. Question

What is the most likely explanation if a backdrafting furnace begins to vent normally when a basement window is opened?

Combustion zone too airtight.
Gas input too low.
Blockage in chimney.
Gas input too high.

4. Question

What is the most serious safety problem caused by an wide-open return plenum on an atmospherically vented furnace?

Flame roll-out.
Air becoming too thin in the combustion zone.
Carbon dioxide in the combustion zone.
Flue-gas spillage.

5. Question

What part of the building enclosure surrounds combustion heating equipment?

CAZ
CFM
Depressurized zone.
WRT

6. Question

Where is the correct sampling location for measuring carbon monoxide (CO) in an appliance equipped with a draft diverter?

Near the flue-gas exit point of the heat exchanger.
At the chimney’s outlet.
In the chimney downstream from the draft diverter.
Directly over the burner.

7. Question

What problem could occur if the combustion gases or the chimney are too cool?

Condensation.
Poor combustion efficiency.
Carbon dioxide pollution.
CAZ depressurization.

8. Question

Which of the following would be least likely to affect chimney draft?

Combustion fuel.
Flue gas temperature.
Chimney diameter.
Chimney height.

9. Question

Which of the following would be most likely to cause downdraft or spillage in a chimney?

Negative pressure in the combustion zone.
High flue-gas temperature.
Operating a dehumidifier.
Opening exterior door.

10. Question

Which test measures the vent pressure of an atmospherically vented appliance?

Draft test.
Carbon dioxide (CO2) test.
Stack temperature test.
Flue velocity test.

11. Question

What safety problem concerns you when you see soot on or near a combustion appliance?

Carbon monoxide.
Carbon dioxide.
Condensation and rust.
Draft is too high.

12. Question

Which of these could reduce or eliminate condensation and rust in the vent near a combustion appliance?

Install a double-wall vent connector.
Decrease the fuel pressure.
Close the draft diverter door.
Install a combustion air opening.

13. Question

At what specific CO level in parts per million would you stop testing a range burner for CO?

70 ppm
9 ppm
35 ppm
1000 ppm