Practice quizzes 5/5 Flashcards
What term is used to describe a burner flame that moves back through the burner nozzle?
Delayed ignition
Lazy flame
Flashback
c
Through which device is fuel discharged to an atmospheric burner?
Orifice
Burner venturi
Burner ports
a
Which type of atmospheric burner produces a single large flame?
Induced draft
Single or mono-port burner
Forced draft
b
Drilled port, drilled pipe, slotted port, and ribbon port are all types of what?
Single port atmospheric burners
Radiant head atmospheric burners
Multiport atmospheric burners
Pulse combustion atmospheric burners
c
What is the recommended maximum port diameter for drilled port atmospheric burners?
No. 29 drill
No. 12 drill
No. 42 drill
No. 56 drill
a
What is the recommended minimum port diameter for drilled port atmospheric burners?
No. 56 drill
No. 12 drill
No. 42 drill
No. 29 drill
c
What type of burner has combustion air supplied by a fan or blower under sufficient pressure to overcome the restriction of the burner and the appliance?
Fan assisted burner
Natural draft burner
Forced draft burner
c
Match the appropriate word(s) to best complete the following statements:
a. The ______ burners use a mechanical device to mix the required amounts of air and gas before ignition
b. The _______ type of burner uses air under pressure to entrain gas at atmospheric pressure
c. The _________ burner provides complete premixing with mechanical mixers
a) premix
b) aspirator
c) blower-mix
What type of burner has a fan located downstream of the combustion zone?
Forced draft burner
Induced draft burner
Atmospheric burner
b
What device is used to regulate gas supply to an aspirator-type burner?
Zero governor
Orifice
Blower mixer
a
Which atmospheric burners are most susceptible to flashback?
Ribbon burners
Ring burners
Mono-port
c
What helps to keep the flame retained at the burner port of a mono-port burner?
Gas pressure
Flame spreader
Crimped ring
c
What is a “multiport” burner susceptible to?
Clogging with lint from the inside
Delayed ignition
Sooting
a
Which of the following is not a way in which heat is transferred?
Vibration
Conduction
Radiation
Convection
a
In which direction does heat energy flow?
It flows from cold to warm
It flows from warm to cold
b
What happens when a fluid is heated?
It expands and becomes lighter
It reduces volume.
It boils
a
What controls the drying period of a gas-fired clothes dryer?
The thermostat
Moisture sensor or timer
The high limit
b
What normally controls the automatic gas valve found on a forced warm-air furnace?
The fan limit control
The air circulating fan
A thermostat mounted in the space being heated
c
Where is the blower located on a down-flow furnace?
Above the heat exchanger
Below the heat exchanger
At the same level as the heat exchanger
a
Name two ways in which the burner can be controlled on a unit heater.
Opening a window, manual shut off valve on the gas line
A wall-mounted thermostat, manual switch
b
What factor must be considered when installing swimming pool heaters that would not be a concern with a hot-water space-heating boiler?
High flow rate
Low return water temperature
Thermostat location
b
Which of the following conditions are not regulated in a Category 1 hot water boiler?
Firing of the boiler
Boiler water temperature
Venting pressure
Circulating pump
c
Which type of water heating system can be used for both domestic hot water supply and space heating?
Combination unit
Any power vented water heater.
Fin-type boiler
a
How is the heat directed to the floor in a low-intensity infrared heater?
By the use of ceiling fan
Through convection
The tubes radiate heat to the reflectors which in turn direct the heat to the floor
c
What three types of gas-fired units are used to heat a single room or other small areas?
Room space heaters, Wall furnace, Baseboard heater
Room space heaters, Steam boiler, Baseboard heater
Baseboard heater, Room space heater, Infrared heater
a
Indicate True or False:
Many gas-fired rooftop units provide both heating and cooling functions.
True
False
true
What is the purpose of an operating aquastat?
To maintain water pressure in a boiler system.
To ensure water flow.
To energize or de-energize the main gas valve in response to the water temperature.
c
Is the temperature setting of a high-limit aquastat higher or lower than the setting of the operating aquastat?
Lower
Higher
The same
b
Does the furnace fan continue to run if the high-limit switch opens the furnace control circuit?
Yes
No
yes
What causes the contacts of a steam boiler operating pressuretrol to open?
The water level in the boiler increases
A rise in steam pressure
The water level in the boiler decreases
b
What activates a flame roll-out switch?
Spillage of flue products from the draft hood opening
The opening of the high limit
A rise in temperature
c
Senses the operation of a circulating pump = ____-______
flow-switch
Senses air movement using a paddle attached to a micro-switch = ________ switch
pressure switch
Allows water to escape if temperature or pressure exceeds a preset value inside a hot water heater = _____
T&P
Turns a boiler or water heater on and off to maintain a desired water temperature = ________ aquastat
operating
Shuts down the burners in the event of a failure to vent flue products from the combustion chamber = ______ _______ ______
flame rollout switch
What does an outdoor reset control system do in a hydronic heating system?
boiler temperature matches outdoor temperature
What are the two sensors involved in outdoor reset control?
- indoor water temperature
- ambient outdoor temperature
What does the outdoor temperature sensor sense?
outdoor temperature
What does the indoor temperature sensor sense?
indoor water temperature
What is a thermistor?
resistance is dependant on temperature changes
What type of thermistor is used for an outdoor temperature sensor?
NTC - negative temperature coefficient
The troubleshooting procedure is broken down into a series of specific steps. What should be your first step?
Make a trial run
Test conclusions
Know the system
Replace the components
c
Suppose that upon testing a furnace, the fan motor will not run. The burner is operating, the heat exchanger temperature is above the fan-on setpoint and the fan switch contacts are open. What should you do?
Replace the fan
Replace transformer
Replace the fan switch
Replace the thermostat
c
Suppose the furnace will not light, thermostat is calling for heat and you get a reading of 24 V across the thermostat connections.
Replace transformer
Replace the gas valve
Replace the fan switch
Replace the thermostat
d
List Thermostats are an example of a control that can be recalibrated or readjusted.
True
False
a
What setting should the multimeter be on when testing the flame sensing circuit?
µAmps DC
µVolts AC
µAmps AC
µVolts DC
a
All IFC will have a fault code retrieval push button on the module.
True
False
b
Using the fault code table in Illustration 4, what component, and its connections, should be tested if the IFC red light is flashing one short flash following by one long flash?
Ignitor
Blower
Gas valve
Flame sensor
c
