HVAC Gas Heat certification exam Questions & 100% Verified Answers | Latest Update | Already Graded A+

A gas furnace is to be installed in a garage. The national standards require that the burners and ignition sources must be located ______ above the floor : 18 inches A good description of how a bi-metal fan switch operates the blower motor on a gas furnace is : Temperature on- temperature off Redundant gas valves used on gas furnaces have : Dual gas shut off seats Burning one cubic foot of liquefied petroleum gas completely will produce approximately ______ BTUs : LP gas has a specific gravity of : 1.5 - 2.0 2 | P a g e What is the purpose of a spoiler screw located on a burner, or adjustable-shutters? : Mix primary air and gas Furnace limit switches are wired in series with the : Gas valve A technician is using an extension ladder to work on roof top unit. The top of the ladder should extend _____ beyond the support point : 3 feet A technician determines that a natural gas furnace has a defective heat exchanger. The technician should : Inform the homeowner and turn the gas off A natural gas furnace usually requires _____ gas pressure at the manifold and burners : 3.5 in. W.C. The vent system for a condensing furnace is classified as ____ by the National Field Gas Code. : Category IV Type B vent pipe must be kept at least _____ from combustible materials 3 | P a g e : One inch Typical condensing furnaces have an AFUE rating of at least : 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 : Point it down The reason heating thermostat have anticipated is to : Reduce lag The typical flue gas temperature of a Category III furnace is : 280°F - 300°F Natural gas primary consists of : Methane Burning one cubic foot of natural gas will produce approximately _____ BTU's : 900~1,100 4 | P a g e A furnace nameplate specifies a temperature rise of 40 to 70 degrees. Temperature measurements indicate a rise of 80 degrees. The most appropriate action is to : Increase fan spee