HVAC Gas Heat certification exam 2024 Questions & Answers Already Passed!!

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 - Answer-18 inches A good description of how a bi-metal fan switch operates the blower motor on a gas furnace is - Answer-Temperature on- temperature off Redundant gas valves used on gas furnaces have - Answer-Dual gas shut off seats Burning one cubic foot of liquefied petroleum gas completely will produce approximately ______ BTUs - Answer- LP gas has a specific gravity of - Answer-1.5 - 2.0 What is the purpose of a spoiler screw located on a burner, or adjustable-shutters? - Answer-Mix primary air and gas Furnace limit switches are wired in series with the - Answer-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 - Answer-3 feet A technician determines that a natural gas furnace has a defective heat exchanger. The technician should - Answer-Inform the homeowner and turn the gas off A natural gas furnace usually requires _____ gas pressure at the manifold and burners - Answer-3.5 in. W.C. The vent system for a condensing furnace is classified as ____ by the National Field Gas Code. - Answer-Category IV Type B vent pipe must be kept at least _____ from combustible materials - Answer-One inchTypical condensing furnaces have an AFUE rating of at least - Answer-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 it down The reason heating thermostat have anticipated is to - Answer-Reduce lag The typical flue gas temperature of a Category III furnace is - Answer-280°F - 300°F Natural gas primary consists of - Answer-Methane Burning one cubic foot of natural gas will produce approximately _____ BTU's - Answer-900~1,100 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 - Answer-Increase fan speed A BTU is the amount of heat required to raise the temperature of one pound of water - Answer-One degree Fahrenheit Natural gas piping must be sized to prevent excessive pressure drops. The maximum pressure drop allowance is approximately - Answer-.5 in. W.C. Gas piping must be installed with a pitch of - Answer-1/4" per 15' run