Gas Heat esco exam Questions And Answers

A gas furnace to be installed in a garage. The national standards requires that the burners and ignition 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 will shut down if gas pressure exceeds: - Answer-13.5 in W.C. (or 1/2 psi) This is the maximum pressure for gas valve operation Burning one cubic foot of Liquefied Petroleum gas completely will produce approximately ____ BTUs. - Answer-2,000 - 2,500 LP gas has a specific gravity of ...? - Answer-1.5 - 2.0 ( actual is 1.5 heavier than air which is 1.0) What is the purpose of a spoiler screw located on a burner, or adjustable-shutters? - Answer-to 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 home owner and turn the gas off. A natural gas furnace usually requires _____ gas pressure AT the manifold and burners. What should the inlet pressure be to the manifold? - Answer-3.5 in WC inlet- 5-7 in WCThe vent system for a condensing furnace is classified as ___ by the National Field Gas Code. - AnswerCategory IV (4) Type B vent pipe must be kept at least ____ from combustible materials. - Answer-one inch Typical 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 down The reason heating thermostats have anticipators is to: - Answer-reduce overshoot The typical fluw gas temperature of a Category III furnace is: - Answer-280 F - 300 F The proper chemical name for natural gas is: - Answer-Methane Burning one cubic foot of natural gas will produce approximately ___ BTU's. - Answer-900-1100 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 National Fuel Gas Code maximum pressure drop allowance is approximately: - Answer-0.35 in WC Gas piping must be installed with a pitch of: - Answer-1/4" per 15' runPipe joint compound should be applied to: - Answer-male threads less two end threads A technician is installing a copper elbow on LP gas line; what should be used? - Answer-15% silver solder To burn one cubic foot of Natural Gas completely, AT LEAST ____ of combustion air must be available. - Answer-10 cu ft. The ignition temperature of Natural Gas is ____ - Answer-1100 F - 1200 F