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2026 NATE GAS AND HEAT EXAM COMPLETE
CURRENT TESTING QUESTIONS AND
DETAILED CORRECT ANSWERS (VERIFIED)
GUARANTEED PASS/TOP-RATED A+.
GAS & HEAT
Maximize your success on the NATE (North American Technician
Excellence) Gas & Heat certification exam with focused
preparation that strengthens your understanding of gas furnace
and boiler systems, including combustion efficiency, venting
requirements, heat exchanger diagnostics, and safety controls.
It is specifically designed for HVAC technicians seeking to
validate their skills in installing, maintaining, and
troubleshooting gas-fueled heating equipment.
The following measurements would be needed to properly
evaluate a complaint of "drafty" operation with a gas heating
system: ✓ ✓...... ANSWER ....... System TD,
Drop and static pressure
A furnace is inoperative because of a failure in the ignition
sequence at the flame proving stage. To check the flame
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proving circuit the technician would: ✓ ✓...... ANSWER
....... Connect a microampmeter set to DC microamps in
the sensor circuit and operate the furnace.
A technician receives a call that a gas furnace is running
constantly in heating and cannot be shut off. While checking
the thermostat, the technician observes the burner shuts off
by removing the wire on the R terminal on the thermostat
subbase. ✓ ✓...... ANSWER ....... Most likely there is a
short in the thermostat subbase.
The continuity of a fuse should be tested by: ✓ ✓......
ANSWER ....... Checking resistance with power off.
A standing pilot furnace uses a relay for controlling the
supply blower. On a call for heat, the burner lights, the fan
control closes, but the blower does not run. A check of
voltage at the blower relay coil shows 24V. The load side
measures 0V. The technician should replace what: ✓ ✓......
ANSWER ....... Fan relay.
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The following is true about fan run capacitors: ✓ ✓......
ANSWER ....... The fan capacitor shifts the electrical
phase angle.
The pressure switch on an induced draft blower system is
not closing properly; the technician can check the pressure
using a: ✓ ✓...... ANSWER ....... Bourdon tube pressure
gauge.
The blower access door is removed from a powered up gas
furnace with a door interlock switch. Assume the switch has
not been modified, the technician read across the door
interlock switch terminals should get: ✓ ✓...... ANSWER
....... Volts
A damaged section of double wall vent pipe is to be replaced
with a section produced by a different manufacturer: ✓
✓...... ANSWER ....... The installer should check the new
section for compatible locking joints.
If too much primary air is used the flame will: ✓ ✓......
ANSWER ....... Lift off the burner.
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What is the problem when a flame on a high efficiency gas
furnace is burning primarily yellow: ✓ ✓...... ANSWER .......
The flame is burning without sufficient combustion air.
The cause of a voltage reading across a closed contact in a
24V control circuit is: ✓ ✓...... ANSWER ....... Pitted or
dirty contacts.
The following are the first two checks typically made on an
electronic control: ✓ ✓...... ANSWER ....... Presence of
any on board transformer voltage.
Proper output voltage.
During a service call on a unit the technician finds that the
wiring diagram is missing from the access panel. The
technician may begin troubleshooting by: ✓ ✓......
ANSWER ....... Tracing the circuits either mentally or on a
sketch pad.
The first check made for most electrical troubleshooting is a:
✓ ✓...... ANSWER ....... Voltage check of the supply line.
2026 NATE GAS AND HEAT EXAM COMPLETE
CURRENT TESTING QUESTIONS AND
DETAILED CORRECT ANSWERS (VERIFIED)
GUARANTEED PASS/TOP-RATED A+.
GAS & HEAT
Maximize your success on the NATE (North American Technician
Excellence) Gas & Heat certification exam with focused
preparation that strengthens your understanding of gas furnace
and boiler systems, including combustion efficiency, venting
requirements, heat exchanger diagnostics, and safety controls.
It is specifically designed for HVAC technicians seeking to
validate their skills in installing, maintaining, and
troubleshooting gas-fueled heating equipment.
The following measurements would be needed to properly
evaluate a complaint of "drafty" operation with a gas heating
system: ✓ ✓...... ANSWER ....... System TD,
Drop and static pressure
A furnace is inoperative because of a failure in the ignition
sequence at the flame proving stage. To check the flame
, Page 2 of 36
proving circuit the technician would: ✓ ✓...... ANSWER
....... Connect a microampmeter set to DC microamps in
the sensor circuit and operate the furnace.
A technician receives a call that a gas furnace is running
constantly in heating and cannot be shut off. While checking
the thermostat, the technician observes the burner shuts off
by removing the wire on the R terminal on the thermostat
subbase. ✓ ✓...... ANSWER ....... Most likely there is a
short in the thermostat subbase.
The continuity of a fuse should be tested by: ✓ ✓......
ANSWER ....... Checking resistance with power off.
A standing pilot furnace uses a relay for controlling the
supply blower. On a call for heat, the burner lights, the fan
control closes, but the blower does not run. A check of
voltage at the blower relay coil shows 24V. The load side
measures 0V. The technician should replace what: ✓ ✓......
ANSWER ....... Fan relay.
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The following is true about fan run capacitors: ✓ ✓......
ANSWER ....... The fan capacitor shifts the electrical
phase angle.
The pressure switch on an induced draft blower system is
not closing properly; the technician can check the pressure
using a: ✓ ✓...... ANSWER ....... Bourdon tube pressure
gauge.
The blower access door is removed from a powered up gas
furnace with a door interlock switch. Assume the switch has
not been modified, the technician read across the door
interlock switch terminals should get: ✓ ✓...... ANSWER
....... Volts
A damaged section of double wall vent pipe is to be replaced
with a section produced by a different manufacturer: ✓
✓...... ANSWER ....... The installer should check the new
section for compatible locking joints.
If too much primary air is used the flame will: ✓ ✓......
ANSWER ....... Lift off the burner.
, Page 4 of 36
What is the problem when a flame on a high efficiency gas
furnace is burning primarily yellow: ✓ ✓...... ANSWER .......
The flame is burning without sufficient combustion air.
The cause of a voltage reading across a closed contact in a
24V control circuit is: ✓ ✓...... ANSWER ....... Pitted or
dirty contacts.
The following are the first two checks typically made on an
electronic control: ✓ ✓...... ANSWER ....... Presence of
any on board transformer voltage.
Proper output voltage.
During a service call on a unit the technician finds that the
wiring diagram is missing from the access panel. The
technician may begin troubleshooting by: ✓ ✓......
ANSWER ....... Tracing the circuits either mentally or on a
sketch pad.
The first check made for most electrical troubleshooting is a:
✓ ✓...... ANSWER ....... Voltage check of the supply line.
