NATE Gas Heating Air Exam

NATE Gas Heating (Air) Exam (Latest Update 2026 / 2027) Study Guide Questions with Answers | Grade A | 100% Correct

Question:

Off delay timer in gas furnace

Answer:

Controls indoor blower off delay

Question:

Continuity check of de-energized relay coil

Answer:

Checked using ohmmeter

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Question:

Thermopile system

Answer:

Generates its own control circuit voltage of 750 mV

Question:

Single stage combination gas valve with thermocouple flame proving circuit

Answer:

Main burner gas flow is in series with pilot gas valve

Question:

Thermocouple pilot flame

Answer:

Should envelop 3/8 to 1/2 inch of thermocouple

Question:

Flame proving circuit on standing pilot gas furnace

Answer:

Pilot solenoid shuts off gas flow to main burner

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Question:

Intermittent pilot gas furnace

Answer:

Pilot is lit on every call for heat

Question:

First check for electrical troubleshooting

Answer:

Voltage check of supply line

Question:

Standing pilot furnace with relay for controlling supply blower

Answer:

Replace the relay to repair unit

Question:

Induced draft, intermittent pilot gas furnace

Answer:

Induced draft motor starts when thermostat calls for heat

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