CORRECT ANSWERS
The Annual Fuel Utilization Efficiency (AFUE) rating for a high-efficiency furnace is -
CORRECT ANSWER 90-98%
Which component of a mid-efficiency furnace moves air/flue gases through the heat
exchanger? - CORRECT ANSWER combustion air blower
On a mid efficiency furnace, what is the name of the safety device that prevents burner
operation if the combustion air blower fails? - CORRECT ANSWER air prove switch
air prove switch is what kind of switch - CORRECT ANSWER single pole
Which device would be used to ignite the fuel in a mid-efficiency gas-fired heating
system? - CORRECT ANSWER spark ignitor
How many roll-out switches are use in a domestic furnace? - CORRECT ANSWER 2
What must be done when adjusting a fan-off delay time in a mid-efficient forced air
heating system with timing pins - CORRECT ANSWER relocate timing jumper
What is the typical time the blower fan off-delay is set for? - CORRECT ANSWER 90 to
240 seconds
What is the purpose of a micro-biocide treated filter? - CORRECT ANSWER To inhibit
the growth of micro-organisms
When installing a common-air exhaust fan, what two terminals on the electronic control
board are used to control R2 - CORRECT ANSWER R and G
What is considered auxiliary equipment in a mid-efficient forced air heating system? -
CORRECT ANSWER exhaust fan
What is the purpose of a high-efficiency filter in a furnace system? - CORRECT
ANSWER to trap particles as small as one micron
What is the purpose of a mid-efficient filter? - CORRECT ANSWER trap and hold small
particles
What is the maximum loading of a 40 VA Class 2 transformer that supplies motorized
valves on a hot water heating boiler? - CORRECT ANSWER 32 VA