Mechanical Practice Exam Questions
and Answers Already Graded A+
What turns off the gas if there is a problem at a water heater and/or gas furnace? answer -
Thermocouple
Where is the only place cross connection is allowed/acceptable? answer - On the Brine Line of
a water ionization system
Appliance fuel connectors shall have a maximum overall length of answer - 6 feet
A water temperature limiting device shall be provided to limit the hot water supplied bathtub or
whirl pool bathtub to a maximum of answer - 120 F
The total fall in a fixture drain due to pipe slope is limited to a maximum of answer - One pipe
diameter
Where a fixture is separately trapped what is the maximum vertical distance permitted fixture
outlet to the trap weir? answer - 24 inches
What chimney part prevents moisture from entering between the brick and the flue? answer -
Chimney cap/crown
Soot on a gas water heater door indicates: answer - Improper combustion (spillage)
Type B vent and hood must be a minimum of how many feet from the end of the vent? answer
- 2 feet from the highest penetration
, P-Trap cannot be greater than_____from the bottom of a lavatory basin or sink answer - 24''
Atmospheric vacuum breakers: answer - Prevent back flow
What minimum clearance from side &bottom of an openable window to forced fan vent gas
appliance? answer - 4'-4'
What is a typical problem with a gas hot water heater supply valve? answer - Carbon Build up
What is the appropriate temperature difference between return and supply A/c? answer - 15-
20 Delta-T
Gas lines enter a room with a water heater and furnace. Where should the shut off valve be
located? answer - At each appliance
Gas dryer supply line is not being used. Check: answer - Gas line is capped
Incomplete combustion of natural gas produces: answer - Carbon Monoxide; Life expectancy is
6 years
Using a mirror and flashlight to view the heat exchanger on a gas furnace allows you to see
answer - Les than 20% of the heat exchanger
The vent connector should slope: answer - Upward going away from the furnace at minimum
quarter inch per foot
How much should a belt deflect when it is under proper tension? answer - About an inch
and Answers Already Graded A+
What turns off the gas if there is a problem at a water heater and/or gas furnace? answer -
Thermocouple
Where is the only place cross connection is allowed/acceptable? answer - On the Brine Line of
a water ionization system
Appliance fuel connectors shall have a maximum overall length of answer - 6 feet
A water temperature limiting device shall be provided to limit the hot water supplied bathtub or
whirl pool bathtub to a maximum of answer - 120 F
The total fall in a fixture drain due to pipe slope is limited to a maximum of answer - One pipe
diameter
Where a fixture is separately trapped what is the maximum vertical distance permitted fixture
outlet to the trap weir? answer - 24 inches
What chimney part prevents moisture from entering between the brick and the flue? answer -
Chimney cap/crown
Soot on a gas water heater door indicates: answer - Improper combustion (spillage)
Type B vent and hood must be a minimum of how many feet from the end of the vent? answer
- 2 feet from the highest penetration
, P-Trap cannot be greater than_____from the bottom of a lavatory basin or sink answer - 24''
Atmospheric vacuum breakers: answer - Prevent back flow
What minimum clearance from side &bottom of an openable window to forced fan vent gas
appliance? answer - 4'-4'
What is a typical problem with a gas hot water heater supply valve? answer - Carbon Build up
What is the appropriate temperature difference between return and supply A/c? answer - 15-
20 Delta-T
Gas lines enter a room with a water heater and furnace. Where should the shut off valve be
located? answer - At each appliance
Gas dryer supply line is not being used. Check: answer - Gas line is capped
Incomplete combustion of natural gas produces: answer - Carbon Monoxide; Life expectancy is
6 years
Using a mirror and flashlight to view the heat exchanger on a gas furnace allows you to see
answer - Les than 20% of the heat exchanger
The vent connector should slope: answer - Upward going away from the furnace at minimum
quarter inch per foot
How much should a belt deflect when it is under proper tension? answer - About an inch
