Alberta Plumber Apprenticeship
Certification Exam (Third Period)
(Questions And Correct Answers With
Rationales 2026
1. What is the primary purpose of a circulating pump in a hydronic
heating system?
A. Increase system pressure
B. Prevent boiler short cycling
C. Move heated water through the distribution piping
D. Reduce air entrainment
Rationale: Hydronic systems rely on pumps to circulate hot water to
emitters; flow is their main function.
2. Which expansion tank type uses a diaphragm to separate air from
water?
A. Open tank
B. Bladder/diaphragm tank
C. Compression tank
D. Gravity tank
Rationale: Diaphragm tanks use a membrane to keep air and water
separated, preventing absorption.
3. The minimum slope for horizontal steam supply lines is typically:
A. 1%
B. 1/8" per foot
C. 1" per 20 ft
,D. Level
Rationale: Steam mains require slope to allow condensate to drain toward
drip points.
4. What is the purpose of a Hartford loop in a steam system?
A. Reduce stack temperature
B. Prevent boiler flooding and backflow
C. Stabilize pressure
D. Increase steam velocity
Rationale: The Hartford loop prevents water from being forced back into
the boiler from the return.
5. A backflow preventer used to protect against high hazard conditions
must be:
A. Double check
B. Atmospheric vacuum breaker
C. Reduced pressure zone assembly (RP)
D. Dual check
Rationale: RP devices are required for high-hazard cross-connection
protection.
6. What is the typical temperature limit for a hydronic radiant floor
system?
A. 180°C
B. 120°C
C. 55°C
D. 100°C
Rationale: Radiant flooring operates at low temperatures to prevent floor
damage and overheating.
7. The device that controls burner operation based on fluid temperature
is the:
A. Aquastat relay
B. Aquastat
C. Thermistor
, D. Pressuretrol
Rationale: An aquastat senses water temperature and controls boiler firing.
8. What type of valve is used for balancing flow in a hydronic system?
A. Gate valve
B. Ball valve
C. Globe valve
D. Check valve
Rationale: Globe valves offer precise throttling, ideal for balancing.
9. What piping material is most common for low-pressure steam
distribution?
A. PEX
B. Steel pipe
C. Copper
D. PVC
Rationale: Steel withstands steam temperatures and pressures safely.
10. A vacuum relief valve on a water heater prevents:
A. Thermal expansion
B. Tank collapse under negative pressure
C. Excess temperature
D. Excess pressure only
Rationale: Vacuum conditions can collapse tanks; relief valves prevent
this.
11. What is the primary purpose of a mixing valve in domestic hot water
systems?
A. Increase hot water pressure
B. Control outlet temperature
C. Eliminate air
D. Boost flow
Rationale: Mixing valves temper hot water for safety.
Certification Exam (Third Period)
(Questions And Correct Answers With
Rationales 2026
1. What is the primary purpose of a circulating pump in a hydronic
heating system?
A. Increase system pressure
B. Prevent boiler short cycling
C. Move heated water through the distribution piping
D. Reduce air entrainment
Rationale: Hydronic systems rely on pumps to circulate hot water to
emitters; flow is their main function.
2. Which expansion tank type uses a diaphragm to separate air from
water?
A. Open tank
B. Bladder/diaphragm tank
C. Compression tank
D. Gravity tank
Rationale: Diaphragm tanks use a membrane to keep air and water
separated, preventing absorption.
3. The minimum slope for horizontal steam supply lines is typically:
A. 1%
B. 1/8" per foot
C. 1" per 20 ft
,D. Level
Rationale: Steam mains require slope to allow condensate to drain toward
drip points.
4. What is the purpose of a Hartford loop in a steam system?
A. Reduce stack temperature
B. Prevent boiler flooding and backflow
C. Stabilize pressure
D. Increase steam velocity
Rationale: The Hartford loop prevents water from being forced back into
the boiler from the return.
5. A backflow preventer used to protect against high hazard conditions
must be:
A. Double check
B. Atmospheric vacuum breaker
C. Reduced pressure zone assembly (RP)
D. Dual check
Rationale: RP devices are required for high-hazard cross-connection
protection.
6. What is the typical temperature limit for a hydronic radiant floor
system?
A. 180°C
B. 120°C
C. 55°C
D. 100°C
Rationale: Radiant flooring operates at low temperatures to prevent floor
damage and overheating.
7. The device that controls burner operation based on fluid temperature
is the:
A. Aquastat relay
B. Aquastat
C. Thermistor
, D. Pressuretrol
Rationale: An aquastat senses water temperature and controls boiler firing.
8. What type of valve is used for balancing flow in a hydronic system?
A. Gate valve
B. Ball valve
C. Globe valve
D. Check valve
Rationale: Globe valves offer precise throttling, ideal for balancing.
9. What piping material is most common for low-pressure steam
distribution?
A. PEX
B. Steel pipe
C. Copper
D. PVC
Rationale: Steel withstands steam temperatures and pressures safely.
10. A vacuum relief valve on a water heater prevents:
A. Thermal expansion
B. Tank collapse under negative pressure
C. Excess temperature
D. Excess pressure only
Rationale: Vacuum conditions can collapse tanks; relief valves prevent
this.
11. What is the primary purpose of a mixing valve in domestic hot water
systems?
A. Increase hot water pressure
B. Control outlet temperature
C. Eliminate air
D. Boost flow
Rationale: Mixing valves temper hot water for safety.
