NATE Gas Heat Questions with Correct Answers |
Latest Update | Guaranteed Pass
3/8 to ½ inch of the end of the thermocouple - CORRECT ANSWER -Should be enveloped by the
pilot flame
A control string is defined as two or more switch contacts connected in a circuit, or set of
circuits, to control a load. In order to troubleshoot a load controlled by a control string, the
technician must first: - CORRECT ANSWER -Check for proper voltage applied across the load.
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. - CORRECT ANSWER -The likely problem with the system is the blower off delay
is set too long.
A customer has concerns about carbon monoxide (CO) in their hone. Many of their reported
symptoms indicate there may indeed be a CO problem but on each trip the technician makes to
check their home the technician finds normal CO levels. - CORRECT ANSWER -CO detector
reader/recorder would be appropriate to use for determining if a problem truly exists.
A damaged section of double wall vent pipe is to be replaced with a section produced by a
different manufacturer: - CORRECT ANSWER -The installer should check the new section for
compatible locking joints.
A dirty or clogged air filter in an operating gas furnace can cause an: - CORRECT ANSWER -
Increase temperature rise.
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: - CORRECT ANSWER -Connect a
microampmeter set to DC microamps in the sensor circuit and operate the furnace.
,A gas clothes dryer can interfere with the operation of a nearby natural draft gas furnace with
an atmospheric burner by: - CORRECT ANSWER -Stealing combustion air preventing complete
fuel burning.
A gas furnace should reach a steady state - CORRECT ANSWER -Before taking a combustion test
A gas furnace with a standing pilot uses a flame switch for proving pilot flame. - CORRECT
ANSWER -Several millivolts are generated by the flame.
A line voltage fuse is sized to protect from: - CORRECT ANSWER -Excessive voltage
A meter reading microfarads is used to: - CORRECT ANSWER -Check a run capacitor with a
capacitance tester.
A packaged unit in a two story installation is to be located at ground level with ductwork
running up the outside wall to a chase in the second floor. - CORRECT ANSWER -The precautions
need to be taken with outside ductwork is it must be insulated and weatherproofed.
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: -
CORRECT ANSWER -Fan relay.
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: - CORRECT ANSWER -The difference
between supply static and return static is unacceptably low.
A system that is oversized for the load: - CORRECT ANSWER -Will cause the unit to short cycle.
, A technician is installing a gas furnace and the customer has decided not to install an air
conditioner. Making this decision, the affect it will have on the installation of the supply
ductwork is: - CORRECT ANSWER -Leave adequate space should be allowed for addition of a coil
in the future when feasible.
A technician measures the return air temperature of a 100,000 BTU output gas furnace to be
65°F and the supply side air temperature is 135°F: - CORRECT ANSWER -The CFM would be
1323.
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. - CORRECT ANSWER -Most
likely there is a short in the thermostat subbase.
A technician should consult WHAT to make an accurate residential load calculation. - CORRECT
ANSWER -Manual J is the ACCA manual.
A technician wishes to determine the air flow of a gas furnace on startup using the temperature
rise method, the following conditions exist: - CORRECT ANSWER -The gas meter has been
clocked and the flow rate has been determined~The gas heating value is known~The heat rise
across the heat exchanger is measured~Next he needs to calculate the CFM using a formula.
A thermopile system usually generates its own control circuit voltage of: - CORRECT ANSWER -
750 mV.
A transformer with a 24V secondary repeatedly fails. The technician determines the load in the
secondary circuit to be - CORRECT ANSWER -2 amps
A typical four-way multipositional gas furnace is converted from upflow to down flow by: -
CORRECT ANSWER -Turning the furnace upside down with specified alterations.
Latest Update | Guaranteed Pass
3/8 to ½ inch of the end of the thermocouple - CORRECT ANSWER -Should be enveloped by the
pilot flame
A control string is defined as two or more switch contacts connected in a circuit, or set of
circuits, to control a load. In order to troubleshoot a load controlled by a control string, the
technician must first: - CORRECT ANSWER -Check for proper voltage applied across the load.
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. - CORRECT ANSWER -The likely problem with the system is the blower off delay
is set too long.
A customer has concerns about carbon monoxide (CO) in their hone. Many of their reported
symptoms indicate there may indeed be a CO problem but on each trip the technician makes to
check their home the technician finds normal CO levels. - CORRECT ANSWER -CO detector
reader/recorder would be appropriate to use for determining if a problem truly exists.
A damaged section of double wall vent pipe is to be replaced with a section produced by a
different manufacturer: - CORRECT ANSWER -The installer should check the new section for
compatible locking joints.
A dirty or clogged air filter in an operating gas furnace can cause an: - CORRECT ANSWER -
Increase temperature rise.
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: - CORRECT ANSWER -Connect a
microampmeter set to DC microamps in the sensor circuit and operate the furnace.
,A gas clothes dryer can interfere with the operation of a nearby natural draft gas furnace with
an atmospheric burner by: - CORRECT ANSWER -Stealing combustion air preventing complete
fuel burning.
A gas furnace should reach a steady state - CORRECT ANSWER -Before taking a combustion test
A gas furnace with a standing pilot uses a flame switch for proving pilot flame. - CORRECT
ANSWER -Several millivolts are generated by the flame.
A line voltage fuse is sized to protect from: - CORRECT ANSWER -Excessive voltage
A meter reading microfarads is used to: - CORRECT ANSWER -Check a run capacitor with a
capacitance tester.
A packaged unit in a two story installation is to be located at ground level with ductwork
running up the outside wall to a chase in the second floor. - CORRECT ANSWER -The precautions
need to be taken with outside ductwork is it must be insulated and weatherproofed.
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: -
CORRECT ANSWER -Fan relay.
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: - CORRECT ANSWER -The difference
between supply static and return static is unacceptably low.
A system that is oversized for the load: - CORRECT ANSWER -Will cause the unit to short cycle.
, A technician is installing a gas furnace and the customer has decided not to install an air
conditioner. Making this decision, the affect it will have on the installation of the supply
ductwork is: - CORRECT ANSWER -Leave adequate space should be allowed for addition of a coil
in the future when feasible.
A technician measures the return air temperature of a 100,000 BTU output gas furnace to be
65°F and the supply side air temperature is 135°F: - CORRECT ANSWER -The CFM would be
1323.
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. - CORRECT ANSWER -Most
likely there is a short in the thermostat subbase.
A technician should consult WHAT to make an accurate residential load calculation. - CORRECT
ANSWER -Manual J is the ACCA manual.
A technician wishes to determine the air flow of a gas furnace on startup using the temperature
rise method, the following conditions exist: - CORRECT ANSWER -The gas meter has been
clocked and the flow rate has been determined~The gas heating value is known~The heat rise
across the heat exchanger is measured~Next he needs to calculate the CFM using a formula.
A thermopile system usually generates its own control circuit voltage of: - CORRECT ANSWER -
750 mV.
A transformer with a 24V secondary repeatedly fails. The technician determines the load in the
secondary circuit to be - CORRECT ANSWER -2 amps
A typical four-way multipositional gas furnace is converted from upflow to down flow by: -
CORRECT ANSWER -Turning the furnace upside down with specified alterations.
