OHIO (OH) HYDRONICS CONTRACTOR TEST QUESTIONS AND ACCURATE ANSWERS

138 QUESTIONS AND ANSWERS


1. What is the primary function of a hydronic heating system? A) To heat
air directly B) To circulate heated water through a piping system C) To generate
steam for heating D) To provide ventilation Answer: B) To circulate heated
water through a piping system
2. What is the typical operating temperature range for a residential
hydronic heating system? A) 100°F - 120°F B) 140°F - 180°F C) 200°F -
240°F D) 60°F - 80°F Answer: B) 140°F - 180°F
3. Which component is responsible for moving water through a hydronic
system? A) Boiler B) Expansion tank C) Circulator pump D) Heat exchanger
Answer: C) Circulator pump
4. What is the purpose of an expansion tank in a hydronic system? A) To
store hot water for domestic use B) To accommodate thermal expansion of
water C) To filter the water D) To regulate water pressure Answer: B) To
accommodate thermal expansion of water
5. In a closed-loop hydronic system, what prevents air from entering the
system? A) Check valve B) Pressure relief valve C) Fill valve D) Air separator
Answer: A) Check valve
6. What is the difference between a one-pipe and two-pipe hydronic
system? A) Number of boilers used B) Supply and return piping configuration
C) Water temperature D) Pump capacity Answer: B) Supply and return
piping configuration
7. What is the recommended minimum water velocity in hydronic piping?
A) 0.5 fps B) 2 fps C) 4 fps D) 6 fps Answer: B) 2 fps
8. What causes water hammer in a hydronic system? A) Air in the system B)
Sudden valve closure C) Low water pressure D) High water temperature
Answer: B) Sudden valve closure

, 9. Which type of heat emitter provides the most even heat distribution? A)
Baseboard radiators B) Panel radiators C) Radiant floor systems D) Fan coil
units Answer: C) Radiant floor systems
10. What is the typical design temperature drop across a hydronic heating
system? A) 10°F B) 20°F C) 30°F D) 40°F Answer: B) 20°F
11. What is the primary advantage of a primary-secondary pumping
system? A) Lower installation cost B) Hydraulic separation of circuits C)
Higher efficiency D) Simpler control Answer: B) Hydraulic separation of
circuits
12. In a hydronic system, what is the purpose of a flow control valve? A) To
prevent backflow B) To regulate water temperature C) To maintain constant
flow rate D) To remove air from the system Answer: C) To maintain constant
flow rate
13. What is the recommended maximum water velocity in hydronic piping
to minimize noise? A) 2 fps B) 4 fps C) 6 fps D) 8 fps Answer: B) 4 fps
14. Which material is commonly used for hydronic piping in residential
applications? A) Cast iron B) Copper C) PVC D) Galvanized steel Answer: B)
Copper
15. What is the purpose of a mixing valve in a hydronic system? A) To
combine supply and return water B) To regulate system pressure C) To remove
impurities D) To control water temperature Answer: D) To control water
temperature
16. What is the typical pressure rating for residential hydronic systems? A)
15 psi B) 30 psi C) 125 psi D) 150 psi Answer: B) 30 psi
17. Which component automatically removes air from a hydronic system?
A) Expansion tank B) Air separator C) Pressure relief valve D) Fill valve
Answer: B) Air separator
18. What is the recommended slope for horizontal hydronic piping? A) 1/8"
per foot toward the boiler B) Level installation C) 1/4" per foot away from the
boiler D) 1/2" per foot toward the expansion tank Answer: A) 1/8" per foot
toward the boiler
19. In a zoned hydronic system, what controls the flow to individual zones?
A) Thermostatic radiator valves B) Zone valves or pumps C) Pressure
regulators D) Temperature sensors Answer: B) Zone valves or pumps