Gas-Fired Heating Systems Exam Review

Flashcards created to help review key concepts and questions from the gas-fired heating systems exam.

What is the required pipe size for section "A" of the gas piping system in Figure 1?

2½"

What is the allowable maximum distance piping supports should be for a horizontal gas line?

20 feet (6 m).

What is the minimum pressure required to test a new gas system that is 220 feet long with a supply pressure of 40 psig?

60 minutes at 50 psig (340 kPa).

Which electrical component in Figure 1 is identified as #2?

Gas valve.

What happens if the adjusting screw of a regulator is turned counter-clockwise, decreasing the spring tension?

The downstream pressure will decrease.

What is the temperature and pressure relief valve setting for most residential type water heaters?

210° F (99° C), 150 psig (1034 kPa).

How often should disposable filters be cleaned before they are replaced?

Once.

What occurs if a 24-volt transformer for a power humidifier is wired in series with the humidistat and the humidifier motor?

The humidifier motor will operate properly.

Which device shuts off the spark igniter in a spark ignition dryer after proper ignition?

Spark sensor.

What is the normal fuse size for #14 AWG copper wire?

15 amps.

What happens when the humidistat for a power humidifier closes?

The humidifier solenoid valve opens.

What is the best method of adjusting and setting the pressure on an appliance regulator?

Adjust the regulator set point using a manometer to the appliance rating.

Which electrical component in Figure 1 is identified as #5?

Transformer.

As the temperature difference between outdoors and indoors increases, what happens to the stack effect?

It always increases the draft action of vented appliances.

What type of burner is used in conversion burners?

Inshot burner.

How often should a refrigerator be serviced and cleaned?

At least once a year or as recommended by the manufacturer.

Which leak testing method is required when adding an appliance to an existing piping system?

Soap or detection instrument and a 10-minute dial test or leak test at normal working pressure.