Gas Furnace Hvac Study Guide

The National Fuel Gas Code classifies a vent system for a condensing furnace as; {Ans: Category IV}LP gas has a specific gravity of; {Ans: 1.5 to 2.0}a furnace that is designed with the blower motor located beneath the heat exchanger is called an {Ans: upflow}when installing the vent pipe for a category IV condensing furnace, the proper pitch for the flue pipe is {Ans: 1/4in per foot}while evaluating a gas valve that failed to open the tech determined, gas valve knob was in the proper position the thermostat was calling for heat, the valve is an electric ignition type, resistance of the main gas valve coil was good proper voltage was present at the main gas valve coil terminal what action should be taken next {Ans: replace the gas valve}the pilot assembly orfice of a spark ignition furnace is completely clogged. The tech should {Ans: replace it}a BTU is the amount of heat required to raise the temp of one pound of water {Ans: one degree fahrenheit}the formula (x=Btu/hr Output) divided (1.08 x TD) is used to calculate {Ans: CFM}how much current is typically conducted through the flame sensor? {Ans: 30-200microamps}air