NATE Gas Heating Exam Questions and answers 2023Since 1992, the United States Department of Energy has required that all furnaces sold and installed from that date on must have an AFUE of no less than: A: 70% B: 75% C: 78% D: 80% - correct answer C: 78%Many pre-1992 furnaces have efficiencies around _______. A: 10% B: 40% C: 60% D: 80% - correct answer C: 60%Today, furnaces with AFUE ratings greater than _____ are available. A: 85% B: 90% C: 100% D: 110% - correct answer B: 90%A thermocouple is used with: A: Intermittent pilot systems B: Direct spark ignition systemsC: Glow coil ignition systems D: Standing pilot ignition systems - correct answer D: Standing pilot ignition systemsThe purpose of the gas pressure regulator is to: A: Keep the color of the flame constant B: Keep the high limit switch from tripping C: Maintain a constant gas pressure at the burner D: Allow the gas valve to operate smoothly and accurately - correct answer C: Maintain a constant gas pressure at the burnerThe instrument used to measure outlet gas pressure is the: A: Velometer B: Anemometer C: Monometer D: Draft gauge - correct answer C: MonometerThe regulator on a