Page 1 of 115
Ohio HVAC Contractor Exam COMPLETE QUESTIONS
AND DETAILED SOLUTIONS LATEST UPDATE THIS YEAR-
JUST RELEASED
✅ SUMMARIZED EXAM COVERAGE (QUICK REVIEW VERSION)
The Ohio HVAC Contractor Exam mainly covers:
• Ohio contractor licensing law, permits, and inspections
• Mechanical code compliance and safety
• Refrigeration cycle, refrigerants, EPA 608 rules
• Electrical troubleshooting, motors, controls
• Gas furnaces, venting, combustion safety, CO prevention
• Boilers/hydronics basics
• Ductwork sizing, airflow, static pressure, IAQ
• Heat pumps, defrost cycles, reversing valves
• Installation best practices and commissioning
• Efficiency ratings and troubleshooting procedures
1.
A contractor begins installing a new rooftop unit without pulling a permit because the customer
requested faster completion. What is the best action?
A) Proceed because customer permission overrides code
, Page 2 of 115
B) Stop and obtain the required permit before continuing installation
C) Proceed and request inspection only after the unit is operating
D) Avoid inspection by labeling the work as “temporary”
Answer: B
Rationale: Ohio code enforcement requires permits for regulated work, and failure may result in fines
and stop-work orders.
2.
During furnace startup, the flame sensor repeatedly shuts down the burners after a few seconds. What
is the most likely cause?
A) Failed blower motor capacitor
B) Dirty flame sensor or poor flame rectification signal
C) Restricted condensate drain line
D) Oversized return duct
Answer: B
Rationale: Flame sensors commonly fail due to contamination, causing loss of flame rectification and
burner shutdown.
, Page 3 of 115
3.
A technician evacuates a refrigeration system but does not use a micron gauge to confirm deep vacuum.
What is the major risk?
A) Compressor will run too quietly
B) Moisture and non-condensables may remain, damaging performance and components
C) System will produce higher airflow
D) Thermostat will stop working permanently
Answer: B
Rationale: Without micron verification, moisture and air may remain, leading to acid formation and
inefficient operation.
4.
A customer reports the air conditioner runs continuously but the house never reaches set temperature
on hot days. What should be checked first?
A) Thermostat battery voltage
B) Airflow restrictions such as dirty filter or blocked evaporator coil
C) Refrigerant type stamped on compressor
D) Outdoor unit paint condition
, Page 4 of 115
Answer: B
Rationale: Low airflow reduces cooling capacity and can cause freezing or poor heat transfer, leading to
long runtimes.
5.
A heat pump enters defrost mode frequently even in mild outdoor temperatures. Which issue is most
likely?
A) Dirty outdoor coil or defective defrost sensor
B) Oversized supply duct
C) Incorrect thermostat anticipator setting
D) Broken condensate pump
Answer: A
Rationale: A dirty coil or faulty sensor causes incorrect temperature readings and excessive defrost
cycling.
6.
Ohio HVAC Contractor Exam COMPLETE QUESTIONS
AND DETAILED SOLUTIONS LATEST UPDATE THIS YEAR-
JUST RELEASED
✅ SUMMARIZED EXAM COVERAGE (QUICK REVIEW VERSION)
The Ohio HVAC Contractor Exam mainly covers:
• Ohio contractor licensing law, permits, and inspections
• Mechanical code compliance and safety
• Refrigeration cycle, refrigerants, EPA 608 rules
• Electrical troubleshooting, motors, controls
• Gas furnaces, venting, combustion safety, CO prevention
• Boilers/hydronics basics
• Ductwork sizing, airflow, static pressure, IAQ
• Heat pumps, defrost cycles, reversing valves
• Installation best practices and commissioning
• Efficiency ratings and troubleshooting procedures
1.
A contractor begins installing a new rooftop unit without pulling a permit because the customer
requested faster completion. What is the best action?
A) Proceed because customer permission overrides code
, Page 2 of 115
B) Stop and obtain the required permit before continuing installation
C) Proceed and request inspection only after the unit is operating
D) Avoid inspection by labeling the work as “temporary”
Answer: B
Rationale: Ohio code enforcement requires permits for regulated work, and failure may result in fines
and stop-work orders.
2.
During furnace startup, the flame sensor repeatedly shuts down the burners after a few seconds. What
is the most likely cause?
A) Failed blower motor capacitor
B) Dirty flame sensor or poor flame rectification signal
C) Restricted condensate drain line
D) Oversized return duct
Answer: B
Rationale: Flame sensors commonly fail due to contamination, causing loss of flame rectification and
burner shutdown.
, Page 3 of 115
3.
A technician evacuates a refrigeration system but does not use a micron gauge to confirm deep vacuum.
What is the major risk?
A) Compressor will run too quietly
B) Moisture and non-condensables may remain, damaging performance and components
C) System will produce higher airflow
D) Thermostat will stop working permanently
Answer: B
Rationale: Without micron verification, moisture and air may remain, leading to acid formation and
inefficient operation.
4.
A customer reports the air conditioner runs continuously but the house never reaches set temperature
on hot days. What should be checked first?
A) Thermostat battery voltage
B) Airflow restrictions such as dirty filter or blocked evaporator coil
C) Refrigerant type stamped on compressor
D) Outdoor unit paint condition
, Page 4 of 115
Answer: B
Rationale: Low airflow reduces cooling capacity and can cause freezing or poor heat transfer, leading to
long runtimes.
5.
A heat pump enters defrost mode frequently even in mild outdoor temperatures. Which issue is most
likely?
A) Dirty outdoor coil or defective defrost sensor
B) Oversized supply duct
C) Incorrect thermostat anticipator setting
D) Broken condensate pump
Answer: A
Rationale: A dirty coil or faulty sensor causes incorrect temperature readings and excessive defrost
cycling.
6.
