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NYC Thermostat Repairer (CUNY) EXAM QUESTIONS AND
CORRECT VERIFIED SOLUTIONS LATEST UPDATE THIS YEAR –
JUST RELEASED
NYC Thermostat Repairer (CUNY) Exam
10-Line Exam Coverage in Points Form
1. Thermostat Types & Systems – Mechanical (bimetallic strip, mercury bulb), digital,
programmable, and Direct Digital Control (DDC) thermostats; pneumatic control systems
with air pressure lines .
2. HVAC Control Circuits – Low-voltage thermostat wiring including terminals R
(power/24V), W (heat), Y (cooling/compressor), G (fan), and C (common return) .
3. Electrical Fundamentals – Series vs parallel circuits, transformers for step-down voltage
(typically 24V), multimeter use (voltage, resistance, continuity), open/short circuit
troubleshooting .
4. Installation & Calibration – Proper mounting (leveling required for mechanical
thermostats), wiring connections, calibration procedures, heat anticipator adjustments .
5. Pneumatic Controls – Air pressure systems, tubing installation and repair,
troubleshooting air leaks and pressure loss, pneumatic thermostat response issues .
6. Troubleshooting Sequence – Systematic approach: power → control signal → output;
verify power supply before replacing components; check wiring continuity; confirm
control signal to equipment .
7. Safety Practices – Lockout/tagout procedures, electrical safety (de-energize circuits
before servicing), personal protective equipment (PPE), identifying frayed/damaged
wiring .
8. Environmental Factors – Thermostat placement considerations: direct sunlight (causes
false high readings), proximity to heating vents or appliances, drafty exterior walls, poor
seals causing false cold readings .
9. System Diagnosis – Short cycling causes, continuous operation faults, differentiating
between thermostat and HVAC equipment issues; proper troubleshooting avoids
unnecessary thermostat replacement .
10. Professional Practices – Work order documentation, preventive maintenance,
supervisory practices (personnel supervision, record-keeping, parts requisitioning),
responding to tenant complaints professionally .
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MCQs with Rationales
1. What is the primary function of a thermostat in an HVAC system?
A) To increase air pressure in the distribution system
B) To sense room temperature and control heating/cooling equipment to maintain the setpoint
C) To regulate electrical service to the entire building
D) To replace boiler safety controls during cold weather
Answer: B
Rationale: A thermostat monitors room temperature and signals the HVAC system to operate
when heating or cooling is needed to maintain the selected setpoint. It does not control
building electrical service or boiler safety controls .
2. A thermostat is set above the current room temperature, but the heating system does not
start. What should the technician check first?
A) Replace the thermostat immediately
B) Verify power supply and control voltage
C) Inspect ductwork for blockages
D) Increase airflow through registers
Answer: B
Rationale: Always verify power before replacing components; the issue may be loss of control
voltage rather than thermostat failure. Diagnosing the power supply first prevents unnecessary
parts replacement .
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3. A thermostat is installed on a wall receiving direct sunlight for most of the day. What is the
most likely system behavior?
A) Accurate readings throughout the day
B) False high readings causing improper cycling
C) Faster heating response time
D) Increased airflow from registers
Answer: B
Rationale: Direct sunlight on a thermostat causes false high temperature readings, causing the
system to cycle improperly and creating occupant discomfort. The thermostat cannot accurately
sense room temperature under these conditions .
4. Which type of thermostat typically uses a bimetallic strip for temperature sensing?
A) Digital thermostat
B) Programmable thermostat
C) Mechanical thermostat
D) Smart thermostat
Answer: C
Rationale: Mechanical thermostats often use bimetallic strips that bend with temperature
changes to open and close electrical contacts. This is a fundamental principle of older
mechanical thermostat design .
5. What voltage is commonly used in low-voltage thermostat control circuits?
A) 120V
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B) 240V
C) 24V
D) 480V
Answer: C
Rationale: Most residential and commercial HVAC thermostats operate on 24 volts AC. This low
voltage is provided by a step-down transformer and is safer for control circuits .
6. What does the "R" terminal on a thermostat represent?
A) Return air
B) Refrigerant
C) Power supply (hot side from transformer)
D) Relay signal
Answer: C
Rationale: The R terminal provides the power supply (hot side) from the low-voltage
transformer to the thermostat. This is the power source for the control circuit .
7. What is the purpose of the "C" (common) wire in modern thermostat wiring?
A) Cooling signal to the compressor
B) Common return path for power completing the circuit
C) Compressor control
D) Condenser power supply
Answer: B
Rationale: The C terminal is the common side of the transformer that completes the low-
NYC Thermostat Repairer (CUNY) EXAM QUESTIONS AND
CORRECT VERIFIED SOLUTIONS LATEST UPDATE THIS YEAR –
JUST RELEASED
NYC Thermostat Repairer (CUNY) Exam
10-Line Exam Coverage in Points Form
1. Thermostat Types & Systems – Mechanical (bimetallic strip, mercury bulb), digital,
programmable, and Direct Digital Control (DDC) thermostats; pneumatic control systems
with air pressure lines .
2. HVAC Control Circuits – Low-voltage thermostat wiring including terminals R
(power/24V), W (heat), Y (cooling/compressor), G (fan), and C (common return) .
3. Electrical Fundamentals – Series vs parallel circuits, transformers for step-down voltage
(typically 24V), multimeter use (voltage, resistance, continuity), open/short circuit
troubleshooting .
4. Installation & Calibration – Proper mounting (leveling required for mechanical
thermostats), wiring connections, calibration procedures, heat anticipator adjustments .
5. Pneumatic Controls – Air pressure systems, tubing installation and repair,
troubleshooting air leaks and pressure loss, pneumatic thermostat response issues .
6. Troubleshooting Sequence – Systematic approach: power → control signal → output;
verify power supply before replacing components; check wiring continuity; confirm
control signal to equipment .
7. Safety Practices – Lockout/tagout procedures, electrical safety (de-energize circuits
before servicing), personal protective equipment (PPE), identifying frayed/damaged
wiring .
8. Environmental Factors – Thermostat placement considerations: direct sunlight (causes
false high readings), proximity to heating vents or appliances, drafty exterior walls, poor
seals causing false cold readings .
9. System Diagnosis – Short cycling causes, continuous operation faults, differentiating
between thermostat and HVAC equipment issues; proper troubleshooting avoids
unnecessary thermostat replacement .
10. Professional Practices – Work order documentation, preventive maintenance,
supervisory practices (personnel supervision, record-keeping, parts requisitioning),
responding to tenant complaints professionally .
, Page 2 of 106
MCQs with Rationales
1. What is the primary function of a thermostat in an HVAC system?
A) To increase air pressure in the distribution system
B) To sense room temperature and control heating/cooling equipment to maintain the setpoint
C) To regulate electrical service to the entire building
D) To replace boiler safety controls during cold weather
Answer: B
Rationale: A thermostat monitors room temperature and signals the HVAC system to operate
when heating or cooling is needed to maintain the selected setpoint. It does not control
building electrical service or boiler safety controls .
2. A thermostat is set above the current room temperature, but the heating system does not
start. What should the technician check first?
A) Replace the thermostat immediately
B) Verify power supply and control voltage
C) Inspect ductwork for blockages
D) Increase airflow through registers
Answer: B
Rationale: Always verify power before replacing components; the issue may be loss of control
voltage rather than thermostat failure. Diagnosing the power supply first prevents unnecessary
parts replacement .
, Page 3 of 106
3. A thermostat is installed on a wall receiving direct sunlight for most of the day. What is the
most likely system behavior?
A) Accurate readings throughout the day
B) False high readings causing improper cycling
C) Faster heating response time
D) Increased airflow from registers
Answer: B
Rationale: Direct sunlight on a thermostat causes false high temperature readings, causing the
system to cycle improperly and creating occupant discomfort. The thermostat cannot accurately
sense room temperature under these conditions .
4. Which type of thermostat typically uses a bimetallic strip for temperature sensing?
A) Digital thermostat
B) Programmable thermostat
C) Mechanical thermostat
D) Smart thermostat
Answer: C
Rationale: Mechanical thermostats often use bimetallic strips that bend with temperature
changes to open and close electrical contacts. This is a fundamental principle of older
mechanical thermostat design .
5. What voltage is commonly used in low-voltage thermostat control circuits?
A) 120V
, Page 4 of 106
B) 240V
C) 24V
D) 480V
Answer: C
Rationale: Most residential and commercial HVAC thermostats operate on 24 volts AC. This low
voltage is provided by a step-down transformer and is safer for control circuits .
6. What does the "R" terminal on a thermostat represent?
A) Return air
B) Refrigerant
C) Power supply (hot side from transformer)
D) Relay signal
Answer: C
Rationale: The R terminal provides the power supply (hot side) from the low-voltage
transformer to the thermostat. This is the power source for the control circuit .
7. What is the purpose of the "C" (common) wire in modern thermostat wiring?
A) Cooling signal to the compressor
B) Common return path for power completing the circuit
C) Compressor control
D) Condenser power supply
Answer: B
Rationale: The C terminal is the common side of the transformer that completes the low-
