Texas HVAC Contractor Practice Test

Answer choices

1. A. Recover refrigerant until head pressure falls, even while the condenser remains blocked.
2. B. Reduce evaporator airflow so the compressor has less heat to reject.
3. C. Restore condenser heat rejection and retest pressure/subcooling under normal airflow.
4. D. Bypass the high-pressure control and continue running until pressures stabilize.

Wrong-answer review

• A. Recover refrigerant until head pressure falls, even while the condenser remains blocked.: Charge changes with a blocked condenser can create an undercharged system.
• B. Reduce evaporator airflow so the compressor has less heat to reject.: Reducing evaporator airflow introduces another fault.
• D. Bypass the high-pressure control and continue running until pressures stabilize.: A high-pressure safety is not bypassed for normal operation.

Answer choices

1. A. Check the affected zone’s VAV command, damper position, delivered airflow, and zone-temperature sensor against the control sequence.
2. B. Increase the central fan speed for the entire building before checking the zone, while trending the relevant control point and equipment response for a complete demand cycle.
3. C. Replace the air-handler cooling coil because one zone is warm.
4. D. Close dampers in comfortable zones until the affected room cools.

Answer choices

1. A. Increase the furnace manifold-pressure adjustment until the inlet pressure rises.
2. B. Measure supply pressure under the representative connected load and evaluate service regulator, piping sizing, and upstream restrictions against code and utility/manufacturer requirements.
3. C. Close gas valves to other appliances permanently so the furnace receives priority.
4. D. Replace the burner orifices with larger ones to compensate for the low inlet pressure.

Answer choices

1. A. Leave the cartons because the opening still has some visible free area.
2. B. Raise the thermostat slowly so the appliances do not need the full combustion-air opening, with the affected branch or circuit monitored through the next normal control transition.
3. C. Remove the obstruction, verify the required combustion-air path remains open, and confirm safe appliance operation.
4. D. Install a stronger exhaust fan to draw more air through the partially blocked opening.

Answer choices

1. A. Confirm the BAS graphics show the air handler as OFF and the fan-status point is false, with the affected branch or circuit monitored through the next normal control transition.
2. B. Read the disconnect handle position and verify the lock is physically attached.
3. C. Ask the building operator whether any emergency power source is connected to the air handler.
4. D. A qualified person tests the circuit elements and exposed electrical parts with appropriate test equipment and checks for possible backfeed or induced voltage.

Answer choices

1. A. $100,000 per occurrence, $200,000 aggregate, and $100,000 products/completed operations, with the resulting airflow and static-pressure relationship recorded for the affected path, while observing the equipment through startup, steady operation, and the next normal shutdown.
2. B. $300,000 per occurrence for property damage and bodily injury, $600,000 aggregate for those claims, and $300,000 aggregate for products and completed operations.
3. C. $300,000 per occurrence, $300,000 aggregate, and no products/completed-operations coverage.
4. D. $600,000 per occurrence, $300,000 aggregate, and $600,000 products/completed operations.

Answer choices

1. A. Increase the blower's programmed airflow to overcome the pinched return section.
2. B. Partially close supply dampers so the return side sees less airflow demand.
3. C. Restore the duct to its required free area and protect it from continued compression.
4. D. Lower the thermostat setpoint to keep the fan running longer at the same restriction.

Answer choices

1. A. Measured supply/return airflow and system balance demonstrate the design airflow rates can be achieved.
2. B. Every balancing damper is fully open, regardless of measured room airflow.
3. C. The blower is on its highest speed, regardless of external static pressure, while monitoring the affected pressure relationship until the system reaches a stable condition.
4. D. The thermostat reaches setpoint once, regardless of individual zone delivery.

Answer choices

1. A. Install a larger refrigerant detector because detector sensitivity directly increases exhaust airflow.
2. B. Increase compressor speed to create more room pressure and push air through the exhaust duct.
3. C. Measure system resistance and inspect louvers, dampers, ducts, and termination for restrictions or installation conditions that prevent the fan from reaching its design operating point.
4. D. Open the machinery-room door permanently and treat the added doorway air as the required exhaust capacity.

Answer choices

1. A. Reuse the old clearance because equipment serving the same load always has the same listing conditions, with the result compared against the equipment’s rated performance at the observed load.
2. B. Measure the old cabinet and preserve that dimension as the required clearance.
3. C. Verify the applicable 2024 code provision and the replacement appliance's current installation instructions.
4. D. Choose a universal 36-inch clearance for every side of every appliance.