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100+ Free ASE H7 HVAC (Transit Bus) Practice Questions

Pass your ASE H7 — Heating, Ventilation & Air Conditioning (Transit Bus) Certification exam on the first try — instant access, no signup required.

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An HVAC controller that resets or loses settings each time the bus is restarted most likely has:

A
B
C
D
to track
2026 Statistics

Key Facts: ASE H7 HVAC (Transit Bus) Exam

50

Total Questions

ASE Transit Bus H7

40

Scored Questions

ASE Transit Bus H7

75 min

Time Limit

ASE Transit Bus H7

55%

A/C System & Component (largest area)

ASE H7 content outline

~$59

ASE Registration Cost

ASE

Prometric

Test Provider

ASE

ASE Transit Bus test H7 is a 50-question exam (40 scored multiple-choice plus 10 unscored research items) with a 75-minute time limit, delivered by Prometric and scored on a criterion-referenced basis set by ASE. A/C System & Component Diagnosis, Service & Repair is by far the largest content area at 55%, followed by HVAC Operating Systems & Related Controls at 25% and Heating & Engine Cooling at 20%. H7 is a professional transit-bus technician certification that counts toward Master Transit Bus Technician qualification and typically requires two years of relevant work experience.

Sample ASE H7 HVAC (Transit Bus) Practice Questions

Try these sample questions to test your ASE H7 HVAC (Transit Bus) exam readiness. Each question includes a detailed explanation. Start the interactive quiz above for the full 100+ question experience with AI tutoring.

1A transit bus roof-mounted A/C unit will not cool. The technician's first step before connecting manifold gauges should be to:
A.Verify the compressor clutch or open-drive belt engages and the evaporator/condenser fans run
B.Recover all refrigerant from the system
C.Replace the receiver-drier
D.Add one pound of R-134a to the system
Explanation: Basic performance diagnosis starts with confirming the system is actually being commanded on: clutch/belt engagement and condenser and evaporator blower operation. Without airflow and a turning compressor, gauge readings are meaningless.
2On a large transit-bus A/C system, refrigerant charge is most accurately set by:
A.Sight glass clarity only
B.Charging by weight to the OEM specification
C.Filling until the low side reaches 30 psi
D.Adding refrigerant until frost forms on the accumulator
Explanation: Large bus systems hold many pounds of refrigerant and use TXV metering, so OEM charge specification by weight is the accurate method. Recover, evacuate, then charge the exact specified mass.
3Tech A says R-134a and R-1234yf must never be mixed in the same system. Tech B says each refrigerant requires its own dedicated recovery/recycling equipment and service fittings. Who is correct?
A.Tech A only
B.Tech B only
C.Both Tech A and Tech B
D.Neither
Explanation: Cross-contaminating refrigerants damages systems and recovery equipment and yields invalid charges. Each refrigerant uses unique service couplers and dedicated recovery machines to prevent mixing.
4A high subcooling reading at the condenser outlet on a TXV transit-bus system, combined with a high head pressure, most likely indicates:
A.Low refrigerant charge
B.A stuck-open TXV
C.A failed evaporator blower
D.Refrigerant overcharge or restricted condenser airflow
Explanation: Excess subcooling means more liquid is backing up in the condenser, which raises head pressure. An overcharge or poor condenser airflow both cause this pattern.
5Which lubricant is correct for an R-134a transit-bus A/C compressor specified for PAG oil?
A.Polyalkylene glycol (PAG) oil of the OEM-specified viscosity
B.Mineral oil
C.Brake fluid
D.SAE 30 engine oil
Explanation: R-134a systems specified for PAG require polyalkylene glycol oil of the exact OEM viscosity. Using the wrong oil causes poor lubrication and compressor failure.
6Before opening a transit-bus A/C system for component replacement, the refrigerant must be:
A.Vented to the atmosphere
B.Recovered with EPA-approved recovery equipment
C.Burned off in the engine
D.Diluted with nitrogen and released
Explanation: Federal regulations prohibit venting refrigerant. Recovery with approved equipment is required before opening any sealed refrigerant component.
7A transit bus A/C system shows low side and high side both low, with poor cooling and bubbles where a sight glass exists. The most likely cause is:
A.Refrigerant overcharge
B.Plugged condenser fins
C.Low refrigerant charge
D.Slipping compressor clutch only
Explanation: Both gauges reading low with poor cooling and bubbles in the liquid line is the classic low-charge signature, often from a leak.
8The purpose of the receiver-drier in a transit-bus TXV A/C system is to:
A.Meter refrigerant into the evaporator
B.Compress the refrigerant vapor
C.Reject heat to ambient air
D.Store liquid refrigerant and remove moisture and debris
Explanation: In a TXV system the receiver-drier stores a liquid reserve, ensures a solid liquid column to the TXV, and its desiccant absorbs moisture while a filter traps debris.
9A thermostatic expansion valve (TXV) on a bus evaporator controls refrigerant flow by maintaining a target:
A.Evaporator superheat
B.Condenser subcooling
C.Compressor discharge temperature
D.Receiver-drier pressure
Explanation: A TXV modulates flow to hold a set evaporator superheat using its sensing bulb, ensuring the evaporator is fully active without flooding the compressor.
10Tech A says a transit-bus system's high head pressure can be caused by air (non-condensables) in the system. Tech B says non-condensables are removed by a proper deep vacuum during evacuation. Who is correct?
A.Tech A only
B.Both Tech A and Tech B
C.Tech B only
D.Neither
Explanation: Non-condensable gases raise head pressure because they do not condense. A deep, sustained evacuation removes air and moisture before charging, preventing the problem.

About the ASE H7 HVAC (Transit Bus) Exam

The ASE H7 Heating, Ventilation & Air Conditioning test is part of the ASE Transit Bus certification series for professional transit-bus technicians. It covers large roof-mounted bus A/C systems, refrigerant handling for R-134a and R-1234yf, compressors, condensers, evaporators, TXV and receiver-drier service, hot-water cabin heating loops with booster pumps, and electronic climate controls with driver and passenger zones. Transit-bus HVAC is severe-service work driven by high passenger heat load, frequent door cycling, and long daily run hours.

Assessment

40 scored multiple-choice (50 total incl. 10 unscored) (official ASE); this practice bank is 100 selected-response items

Time Limit

75 minutes

Passing Score

Criterion-referenced (set by ASE)

Exam Fee

~$59 (ASE registration) (ASE (National Institute for Automotive Service Excellence))

ASE H7 HVAC (Transit Bus) Exam Content Outline

55%

A/C System & Component Diagnosis, Service & Repair

Performance temperature testing, manifold-gauge diagnosis, superheat and subcooling, refrigerant charge by weight, recovery/recycle/recharge, leak detection and UV dye, compressors and clutches, condensers, evaporators, TXV, receiver-drier, PAG/POE oil, and R-134a/R-1234yf handling on large roof-mounted bus units.

20%

Heating & Engine Cooling Systems Diagnosis, Service & Repair

Hot-water heating loops, heater cores, heater control (water) valves, electric coolant booster pumps, coolant specification and bleeding, engine thermostat, pressure caps, and cooling-system pressure testing as they affect cabin heat and defrost.

25%

HVAC Operating Systems & Related Controls Diagnosis & Repair

Electronic climate controllers, blend-air dampers and actuators, cabin and ambient temperature sensors, blower speed controls, fresh-air/recirculation, defrost, driver versus passenger zones, scan-tool bidirectional testing, fault codes, and controller configuration and calibration.

How to Pass the ASE H7 HVAC (Transit Bus) Exam

What You Need to Know

  • Passing score: Criterion-referenced (set by ASE)
  • Assessment: 40 scored multiple-choice (50 total incl. 10 unscored) (official ASE); this practice bank is 100 selected-response items
  • Time limit: 75 minutes
  • Exam fee: ~$59 (ASE registration)

Keys to Passing

  • Complete 500+ practice questions
  • Score 80%+ consistently before scheduling
  • Focus on highest-weighted sections
  • Use our AI tutor for tough concepts

ASE H7 HVAC (Transit Bus) Study Tips from Top Performers

1Spend the most time on the A/C area: it is 55% of the exam and includes charge by weight, superheat/subcooling, recovery/recharge, and manifold-gauge diagnosis.
2Memorize that R-134a and R-1234yf must never be mixed and each requires dedicated recovery equipment and unique service fittings.
3Practice reading superheat and subcooling together to separate undercharge, overcharge, restriction, and TXV faults on large bus systems.
4Understand bus heating: hot-water loops with electric booster pumps explain weak heat at idle and the need to bleed long coolant lines.
5Know electronic climate control diagnosis: pull fault codes, verify controller power/ground and sensor data, and use scan-tool bidirectional actuator tests.
6Drill Tech A / Tech B items by deciding whether each statement is independently true before choosing a combined answer.

Frequently Asked Questions

How many questions are on the ASE H7 exam?

The ASE Transit Bus H7 test has 50 total questions, of which 40 are scored multiple-choice and 10 are unscored research items that do not count toward your result. This free practice bank provides 100 selected-response questions so you can practice well beyond the live exam length.

How long is the ASE H7 exam and how is it scored?

You have 75 minutes to complete H7. ASE scores its certification tests on a criterion-referenced basis, meaning the passing standard is set by ASE rather than a fixed published percentage or a curve against other candidates.

What does ASE H7 cover?

H7 covers three content areas for transit-bus HVAC: A/C System & Component Diagnosis, Service & Repair, Heating & Engine Cooling Systems, and HVAC Operating Systems & Related Controls. The A/C area is the largest at 55%, reflecting the large roof-mounted units, refrigerant handling, and refrigeration-cycle diagnosis these buses require.

Is ASE H7 a professional certification?

Yes. ASE H7 is part of the professional ASE Transit Bus technician series and counts toward Master Transit Bus Technician qualification. It is intended for working transit-bus technicians and typically requires two years of relevant hands-on work experience, with up to one year substitutable by approved training.

How much does ASE H7 cost and where is it taken?

Plan for roughly $59 in ASE registration costs; confirm the current amount with ASE before registering. Initial ASE certification tests, including Transit Bus H7, are delivered at Prometric test centers.

What HVAC-specific topics should I focus on for H7?

Focus on refrigerant charge by weight, recovery/recycle/recharge for R-134a and R-1234yf, superheat and subcooling interpretation, manifold-gauge and performance temperature testing on large roof units, hot-water heating loops with booster pumps, and electronic climate controls with blend-air actuators and driver/passenger zones.