ABSA 4A ACTUAL TEST PAPERS 2025/2026 QUESTIONS
WITH ANSWERS GRADED A+
✔✔Infrared heaters are usually mounted
a) overhead
b) on walls
c) in floors
d) under windows
e) over doors - ✔✔A
✔✔Gas-fired infrared heaters use the principle of
a) heating a gas
b) heating a solid surface
c) heating a liquid
d) heating a porous material
e) all of the above - ✔✔B
✔✔In an internally fired, gas fired infrared heater, the
surface temperature is about
a) 300 degrees C
b) 400 degrees C
c) 500 degrees C
d) 600 degrees C
e) 700 degrees C - ✔✔B
✔✔A low temperature catalytic heater contains a layer of
a) metal impregnated with a catalyst
b) wool fibre impregnated with a catalyst
c) plastic fibre impregnated with a catalyst
d) glass wool impregnated with a catalyst
e) porous glass impregnated with a catalyst - ✔✔D
✔✔The quartz lamp heating element will respond
a) instantaneously
b) in a few seconds
c) in about one minute
d) in about thirty seconds
e) in about three minutes - ✔✔B
✔✔The main disadvantage of electric heating is the
a) high maintenance cost
b) poor local temperature control
c) expensive installation
d) high operating cost
,e) all of the above - ✔✔D
✔✔In an open wire type heating element the resistance wire is
made of
a) tungsten
b) magnesium oxide
c) mica
d) steel
e) nickel-chromium - ✔✔E
✔✔Electrical heating can be divided into two general groups:
a) floor and wall
b) direct and indirect
c) wall and baseboard
d) radiant panel and infrared
e) direct and infrared - ✔✔B
✔✔In an electric snow melting unit, a thermostat should be used
to automatically shut the system down when the outdoor
temperature is above
a) 0 degrees C
b) 1 degrees C
c) 2 degrees C
d) 3 degrees C
e) 4 degrees C - ✔✔C
✔✔The basic types of heating systems are:
1. steam heating
2. hot water heating
3. warm air heating
4. electric heating
a) 1, 2, 4
b) 1, 2, 3
c) 2, 3, 4
d) 1, 2, 3, 4
e) 3, 4
Heating Boiler Feedwater Controls - ✔✔D
✔✔When a boiler equipped with a combination feedwater control
and low-water cutoff device shuts down due to a low-water
condition
a) the feedwater flow will also stop
b) level must be restored to above the cutoff line before
the unit can be restarted
c) it can be restarted by simply resetting the cutoff switch
,d) a manual reset switch must be used
e) a prepurge will not be necessary - ✔✔B
✔✔An electric feeder valve will
a) eliminate the need for a low-water fuel cutoff
b) prevent a low-water trip
c) open before the low-water cutoff line is reached
d) require manual action to open
e) open after the unit trips on low-water - ✔✔C
✔✔A float operated mechanical feeder valve should
a) be a normally closed valve
b) open just after the low-water cutoff switch opens
c) be located above the water column
d) not be deemed a stand-by device
e) not open until the level is well below the feed pump
cut-in level - ✔✔E
✔✔In nearly all LP steam heating systems the feedwater
a) is usually condensate
b) requires daily close scrutiny of chemical values
c) is a high make-up percentage
d) must be deaerated
e) requires preheating in an economiser - ✔✔A
✔✔A Hartford loop will
a) eliminate the need for venting a steam heating system
b) ensure continuous circulation of a hot water system
c) prevent steam from entering a steam pressure gage
d) prevent boiler water level from going below the LPWL
e) prevent the draining of an expansion tank - ✔✔D
✔✔Because of variations in flow rate, nearly all large steam
heating plants utilize
a) an economiser
b) a deaerator
c) a condensate receiver
d) multiple boilers
e) steam pressure regulating valves - ✔✔C
✔✔Heating plants with multiple boilers often have
a) independent boiler feedwater control from a header
b) individual feedwater systems
c) feedwater pressure regulating valves for each boiler
d) separate condensate receivers
, e) a common feedwater control valve - ✔✔A
✔✔Dissolved oxygen in condensate
a) will cause pitting in a boiler
b) can cause pitting on the return lines
c) causes grooving of the condensate lines
d) cannot be removed with chemicals
e) necessitates the installation of a deaerator - ✔✔A
✔✔Neutralizing amines
a) raise the pH of condensate
b) lower the pH of boiler water
c) eliminate boiler pitting
d) can cause return grooving
e) absorb carbon dioxide - ✔✔A
✔✔The result of a condensate receiver which is too small could
be
a) high boiler water level(s)
b) loss of condensate to the sewer
c) loss of make-up water
d) unacceptable high steam pressures
e) low make-up water flow rates - ✔✔B
✔✔A feedwater make-up system should
a) utilize demineralizers
b) utilize a deaerator
c) be able to satisfy normal firing needs
d) always be softened water
e) be able to satisfy the needs of at least one boiler in a
multiboiler plant - ✔✔C
✔✔Equalizing lines on a condensate receiver float chamber
a) will dampen level fluctuations
b) keep receiver level equal to boiler level
c) maintain make-up flow equal to condensate flow
d) eliminate the need for a make-up level control valve
e) maintains equal flow of condensate to multiple boilers - ✔✔A
✔✔A condensate receiver low level cutoff switch will
a) act to open a make-up solenoid
b) stop the feedpump thereby preventing damage to it
c) act to close boiler fuel valve(s)
d) sound an alarm
e) cause the make-up valve to close
WITH ANSWERS GRADED A+
✔✔Infrared heaters are usually mounted
a) overhead
b) on walls
c) in floors
d) under windows
e) over doors - ✔✔A
✔✔Gas-fired infrared heaters use the principle of
a) heating a gas
b) heating a solid surface
c) heating a liquid
d) heating a porous material
e) all of the above - ✔✔B
✔✔In an internally fired, gas fired infrared heater, the
surface temperature is about
a) 300 degrees C
b) 400 degrees C
c) 500 degrees C
d) 600 degrees C
e) 700 degrees C - ✔✔B
✔✔A low temperature catalytic heater contains a layer of
a) metal impregnated with a catalyst
b) wool fibre impregnated with a catalyst
c) plastic fibre impregnated with a catalyst
d) glass wool impregnated with a catalyst
e) porous glass impregnated with a catalyst - ✔✔D
✔✔The quartz lamp heating element will respond
a) instantaneously
b) in a few seconds
c) in about one minute
d) in about thirty seconds
e) in about three minutes - ✔✔B
✔✔The main disadvantage of electric heating is the
a) high maintenance cost
b) poor local temperature control
c) expensive installation
d) high operating cost
,e) all of the above - ✔✔D
✔✔In an open wire type heating element the resistance wire is
made of
a) tungsten
b) magnesium oxide
c) mica
d) steel
e) nickel-chromium - ✔✔E
✔✔Electrical heating can be divided into two general groups:
a) floor and wall
b) direct and indirect
c) wall and baseboard
d) radiant panel and infrared
e) direct and infrared - ✔✔B
✔✔In an electric snow melting unit, a thermostat should be used
to automatically shut the system down when the outdoor
temperature is above
a) 0 degrees C
b) 1 degrees C
c) 2 degrees C
d) 3 degrees C
e) 4 degrees C - ✔✔C
✔✔The basic types of heating systems are:
1. steam heating
2. hot water heating
3. warm air heating
4. electric heating
a) 1, 2, 4
b) 1, 2, 3
c) 2, 3, 4
d) 1, 2, 3, 4
e) 3, 4
Heating Boiler Feedwater Controls - ✔✔D
✔✔When a boiler equipped with a combination feedwater control
and low-water cutoff device shuts down due to a low-water
condition
a) the feedwater flow will also stop
b) level must be restored to above the cutoff line before
the unit can be restarted
c) it can be restarted by simply resetting the cutoff switch
,d) a manual reset switch must be used
e) a prepurge will not be necessary - ✔✔B
✔✔An electric feeder valve will
a) eliminate the need for a low-water fuel cutoff
b) prevent a low-water trip
c) open before the low-water cutoff line is reached
d) require manual action to open
e) open after the unit trips on low-water - ✔✔C
✔✔A float operated mechanical feeder valve should
a) be a normally closed valve
b) open just after the low-water cutoff switch opens
c) be located above the water column
d) not be deemed a stand-by device
e) not open until the level is well below the feed pump
cut-in level - ✔✔E
✔✔In nearly all LP steam heating systems the feedwater
a) is usually condensate
b) requires daily close scrutiny of chemical values
c) is a high make-up percentage
d) must be deaerated
e) requires preheating in an economiser - ✔✔A
✔✔A Hartford loop will
a) eliminate the need for venting a steam heating system
b) ensure continuous circulation of a hot water system
c) prevent steam from entering a steam pressure gage
d) prevent boiler water level from going below the LPWL
e) prevent the draining of an expansion tank - ✔✔D
✔✔Because of variations in flow rate, nearly all large steam
heating plants utilize
a) an economiser
b) a deaerator
c) a condensate receiver
d) multiple boilers
e) steam pressure regulating valves - ✔✔C
✔✔Heating plants with multiple boilers often have
a) independent boiler feedwater control from a header
b) individual feedwater systems
c) feedwater pressure regulating valves for each boiler
d) separate condensate receivers
, e) a common feedwater control valve - ✔✔A
✔✔Dissolved oxygen in condensate
a) will cause pitting in a boiler
b) can cause pitting on the return lines
c) causes grooving of the condensate lines
d) cannot be removed with chemicals
e) necessitates the installation of a deaerator - ✔✔A
✔✔Neutralizing amines
a) raise the pH of condensate
b) lower the pH of boiler water
c) eliminate boiler pitting
d) can cause return grooving
e) absorb carbon dioxide - ✔✔A
✔✔The result of a condensate receiver which is too small could
be
a) high boiler water level(s)
b) loss of condensate to the sewer
c) loss of make-up water
d) unacceptable high steam pressures
e) low make-up water flow rates - ✔✔B
✔✔A feedwater make-up system should
a) utilize demineralizers
b) utilize a deaerator
c) be able to satisfy normal firing needs
d) always be softened water
e) be able to satisfy the needs of at least one boiler in a
multiboiler plant - ✔✔C
✔✔Equalizing lines on a condensate receiver float chamber
a) will dampen level fluctuations
b) keep receiver level equal to boiler level
c) maintain make-up flow equal to condensate flow
d) eliminate the need for a make-up level control valve
e) maintains equal flow of condensate to multiple boilers - ✔✔A
✔✔A condensate receiver low level cutoff switch will
a) act to open a make-up solenoid
b) stop the feedpump thereby preventing damage to it
c) act to close boiler fuel valve(s)
d) sound an alarm
e) cause the make-up valve to close
