NATE GAS HEATING CERTIFICATION
SCRIPT 2026 COMPLETE QUESTIONS AND
CORRECT ANSWERS
◉The technician is checking the operation of an induced draft
furnace with an atmospheric burner and a direct ignition system. On
a call for heat the sequence is what? Answer: ~Vent blower comes
on
~Igniter glows
~Main burner does not light
~The next check would be the gas supply and/or gas valve
◉The technician is servicing a gas furnace located in a basement and
the complaint is "not enough heat". The following conditions exist:
Answer: Properly sized furnace is operating correctly
Temperature rise is within specification
Filter is clean and CFM from blower is proper
The most likely problem with this system is the air side is leaking at
one or more supply ducts.
,◉The complaint is that there is static electricity throughout the
house. The home has a bypass humidifier. The technician has
checked the humidistat and verified that it is set properly. Answer:
The next check would be to see if the humidifier damper is open.
◉A customer complains the unit is "blowing cold air". The
technician determines that the problem occurs at the end of the
heating sequence. The furnace used an electronic integrated blower
control. Answer: The likely problem with the system is the blower
off delay is set too long.
◉Undersized ductwork often causes: Answer: ~High sound levels
~Insufficient air quantities
~High static pressures.
◉For accuracy, the preferred locations for the temperature probes
when measuring temperature rise across a heat exchanger in a gas
furnace is to: Answer: ~Read inlet temperature in the return
plenum as close as possible to the heat exchanger.
~Read outlet temperature in supply plenum as close as possible, but
beyond "line of sight" to the heat exchanger.
◉A system airflow check determines that supply static is 0.15 in.
W.C. and return static is a negative 0.55 in. W.C. these readings tell
, the technician: Answer: The difference between supply static and
return static is unacceptably low.
◉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 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
SCRIPT 2026 COMPLETE QUESTIONS AND
CORRECT ANSWERS
◉The technician is checking the operation of an induced draft
furnace with an atmospheric burner and a direct ignition system. On
a call for heat the sequence is what? Answer: ~Vent blower comes
on
~Igniter glows
~Main burner does not light
~The next check would be the gas supply and/or gas valve
◉The technician is servicing a gas furnace located in a basement and
the complaint is "not enough heat". The following conditions exist:
Answer: Properly sized furnace is operating correctly
Temperature rise is within specification
Filter is clean and CFM from blower is proper
The most likely problem with this system is the air side is leaking at
one or more supply ducts.
,◉The complaint is that there is static electricity throughout the
house. The home has a bypass humidifier. The technician has
checked the humidistat and verified that it is set properly. Answer:
The next check would be to see if the humidifier damper is open.
◉A customer complains the unit is "blowing cold air". The
technician determines that the problem occurs at the end of the
heating sequence. The furnace used an electronic integrated blower
control. Answer: The likely problem with the system is the blower
off delay is set too long.
◉Undersized ductwork often causes: Answer: ~High sound levels
~Insufficient air quantities
~High static pressures.
◉For accuracy, the preferred locations for the temperature probes
when measuring temperature rise across a heat exchanger in a gas
furnace is to: Answer: ~Read inlet temperature in the return
plenum as close as possible to the heat exchanger.
~Read outlet temperature in supply plenum as close as possible, but
beyond "line of sight" to the heat exchanger.
◉A system airflow check determines that supply static is 0.15 in.
W.C. and return static is a negative 0.55 in. W.C. these readings tell
, the technician: Answer: The difference between supply static and
return static is unacceptably low.
◉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 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
