HVAC Gas Heat Exams Study Guide 2025: Practice Questions & Answers

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HVAC GAS HEAT EXAMS (LATEST 2025 UPDATES

BUNDLE PACKAGE WITH COMPLETE SOLUTIONS)

100% CORRECT QUESTIONS AND VERIFIED ANSWERS

| GRADE A

A gas furnace is to be installed in a garage . National standards

require that the burners and ignition sources must be located

above the floor ; .....ANSWER.....18 inches

3 . Redundant gas valves used on gas furnaces have ;

.....ANSWER.....B. no manual gas shut off .

Burning one cubic foot of liquified petroleum ( LP ) gas

completely will produce approximately ; .....ANSWER.....D.

2,000-2,500 Btu .

Liquified petroleum ( LP ) gas has a specific gravity of ;

.....ANSWER.....C. 1.5-2.0 .

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What is the purpose of using an adjustable shutter on older

burners ? .....ANSWER.....Mix primary air and gas

The primary function of the limit switch is to de - energize the ;

.....ANSWER.....C. gas valve if the furnace overheats .

A technician is using an extension ladder to work on a roof top

unit . The top of the ladder should extend beyond the support

point by ; .....ANSWER.....C. 3 feet .

A technician determines that a natural gas furnace has a

defective heat exchanger , The technician should ;

.....ANSWER.....Inform the homeowner and turn off the gas supply

to the furnace

The gas pressure usually required at the manifold and burners in

a natural gas furnace is ; .....ANSWER.....3.5 inches WC

The National Fuel Gas Code classifies a vent system for a

condensing furnace as ; .....ANSWER.....D. Category IV

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The minimum distance Type - B vent pipe must be kept from

combustible materials is ; .....ANSWER.....D. one inch .

Typical condensing furnaces have an efficiency rating of at least

; .....ANSWER.....D. 90 % .

You have installed a Category IV , two - pipe vent system that

terminates through the roof of the residence . The elbow for the

combustion air intake , above the roof , should ;

.....ANSWER.....point down .

The reason heating thermostats have anticipators or cycle rate

adjustment is to .....ANSWER.....reduce temperature swing .

Higher system efficiency is achieved in a category IV condensing

furnace when the water vapor in the flue gas condenses and

releases ; .....ANSWER.....dioxide latent heat .

Natural gas consists primarily of ; .....ANSWER.....B. methane .