Burning one foot of natural gas will produce - correct answers ✔✔900-1100 btu
The National Fuel Gas Code classifies a vent system for a condensing furnace - correct answers
✔✔Category IV
What type of draft is used to move flue gas through the heat exchanger and into the venting
system in a modern gas fired furnaces - correct answers ✔✔Mechanical
A customer complains that's a 2 year old direct hot surface ignition furnace will not light.the
inducer motor runs,the pressure switch closes and the igniter begins to glow but there is no
ignition.the furnace locks out while attempting to light.after resetting the furnace 17 VAC is
measured at the gas valve and the technician concludes - correct answers ✔✔The gas valve is
shorted
The efficiency rating of a gas burning appliance is determined using - correct answers ✔✔AFUE-
Annual Fuel Utilization Efficiency
When the burners of a furnace are ignited the blower motor operation is delayed too - correct
answers ✔✔Allow the heat exchanger to warm up
Typical condensing furnaces have an efficiency rating of at least - correct answers ✔✔90%
A gas furnace has an integrated furnace control (IFC) how is the fan cycled during heating ? -
correct answers ✔✔Heat relay
, What reading should a good thermocouple produce on a dc meter - correct answers ✔✔30
millivolts
A furnace nameplate specifies a temperature rise of 40 to 70 degrees.temperature
measurements indicate a rise of 80 degrees.the most appropriate action is to - correct answers
✔✔Increase fan speed
The most common burner used in induced draft furnaces is - correct answers ✔✔Inshot
You are installing 1/2 and 3/4 black iron pipe to a natural gas furnace when threading what is
the approximate number of threads to cut - correct answers ✔✔7-10
When exposed to low concentrations of carbon monoxide healthy adults may exhibit - correct
answers ✔✔Headaches and nausea
If voltage is applied across two speed terminals on a fan motor at the same time the motor will -
correct answers ✔✔Short out/burn out
To react to a change in temperature the fan/limit switch in a standing pilot furnace uses a helical
shaft made of - correct answers ✔✔Bi-metal
How much combustion air is required to burn and properly vent one cubic foot of natural gas -
correct answers ✔✔10 cu ft.
Most thermostats contain one or more sets of contacts to control the heating system of a
conditioned space.these contacts - correct answers ✔✔Are thermally actuated
Carbon monoxide(CO) is dangerous. What is the maximum level of undiluted CO that is
acceptable in a sample of the flue gas - correct answers ✔✔400 ppm(parts per million)