GAS S F

Question 1

rating plates on appliances would most likely have an in put rating given in:

Answer 1

BTUH in imperial AND KW in SI (metric)

Question 2

what is the minimum diameter test gauge that can be used for testing gas lines?

Answer 2

3”

Question 3

which of the followingcould cause the regulator to supply too high an outlet pressure?

Answer 3

ruptured diaphragm

Question 4

what is the most common cause of increased C02 in vent gases?

Answer 4

good combustion (co2 is a sign of efficiency)

Question 5

the diagram below would utilize which type of flame detection method?

Answer 5

Flame rod

Question 6

what is the maximum high limit setting for a low pressure steam boiler pressuretrol?

Answer 6

15 psig

Question 7

A tube type radiant heater is considered to be __________ Intensity

Answer 7

low

Question 8

why have flame conductivity systems not been used for proving flames?

Answer 8

the system will not distinguish between a flame and a short to ground.

Question 9

who is responsible for instructing the customer on safe operation of appliances?

Answer 9

the installer of the appliance

Question 10

how is a voltmeter connected to a circuit?

Answer 10

in parallel with power off

Question 11

what may a green flame in a residential furnace indicate?

Answer 11

a refrigerant leak

Question 12

with direct reference to a DFMAH (A direct-fired make-up air heater) utilising a M-Trac controller, what secondary function did the discharge sensor provide?

Answer 12

Low-limit sensor

Question 13

which combustion chamber design is not suitable for conversion?

Answer 13

revertible

Question 14

rating plate efficiency does not take into account:

Answer 14

combustion chamber design

Question 15

what type of efficiency is used to describe the overall efficiency of an appliance?

Answer 15

annual fuel utilisation efficiency (AFUE)

its on a seperate sticker

Question 16

the “flame spectrum” consists of:

Answer 16

visible, infrared and ultraviolet.

Question 17

on a direct-spark ignition system, what happens after the module conducts the safe start test?

Answer 17

pre-purge is established

Question 18

if the temperature on a forced air furnace reaches 280 deg F the most apparent problem is:

Answer 18

the high limit

Question 19

a residential water heater that is 70% efficient , with an input of 70 MBH will heat how many imperial gallons of water in one hour?

(incoming water temperature is 34 deg F and the temperature control is set at normal.)

Answer 19

46.2

Question 20

the proper course of action if the valve let-by is detected on a combustion gas valve is to:

Answer 20

replace the valve

Question 21

what type of a support is required on a counter-flow furnace being installed on a combustible floor?

Answer 21

a factory supplied base

Question 22

what is the acceptable range for the high limit setting on a conventional appliance?

Answer 22

180 deg F - 250 deg F

Question 23

a power unit on a 600 MBH boiler that drops out at 1 mv after 155 seconds:

Answer 23

must be replaced

MVis too low

Question 24

when using an analog meter to test a DC circuit, if the red lead was hooked up to the neutral and the black lead was hooked up to the hot, what would happen to the meter?

Answer 24

the needle would move backwards

Modern meters have correction for inverted lead placement

Question 25

a gas pilot that is extinguished after the main flame is established would best be described as:

Answer 25

interrupted

Question 26

all the control wiring must:

Answer 26

be installed in accordance with the manufacturer’s wiring diagram

Question 27

a gas with high flame speed would most likely give problems with:

Answer 27

extinction pop

Question 28

when using automatic louvres for combustion air supply to an appliance they must:

Answer 28

be interlocked with the main gas valve.

Question 29

you have an appliance with 79% efficiency. the input is 135 MBH what is the FT3 per hour this appliance will use if its firing natural gas

Answer 29

135 CFH Its using all the gas

Question 30

the best description of the symbal is:

Answer 30

combustion air switch