ONTARIO OIL BURNER TECHNICIAN 2 (OBT2) CERTIFICATION EXAM PRACTICE TEST
QUESTIONS AND CORRECT ANSWERS (VERIFIED ANSWERS) PLUS RATIONALES 2026 Q&A
| INSTANT DOWNLOAD PDF.
Core Domains
Fuel oil combustion theory.
Oil burner components and controls.
Installation and servicing procedures.
Troubleshooting and diagnostics.
Electrical circuits and safety controls.
Venting, draft, and combustion air.
Codes, standards, and regulatory compliance.
Occupational health, safety, and professional practice.
Introduction
,This assessment is designed to measure the knowledge and decision-making expected of an Ontario Oil
Burner Technician 2 candidate. It covers theory, practical application, safety, regulatory compliance, and
workplace judgment in situations that reflect real servicing and installation work. Questions combine
multiple-choice knowledge checks with scenario-based problems to assess how well a technician can select
safe, code-compliant, and effective actions in the field. The format emphasizes applied understanding,
diagnostic reasoning, and professional responsibility. Each item is written to support exam preparation by
reinforcing correct procedures, common faults, and the standards expected in fuel-burning appliance work.
Section One
,. Which statement best describes the primary function of an oil burner primary control?
A. It measures room temperature and starts the blower.
B. It regulates domestic hot water supply pressure.
C. It controls fuel delivery and shuts down on flame failure.
D. It increases chimney draft during start-up.
🟢 Correct answer: C
🔴 RATIONALE: The primary control supervises burner operation, proving flame and locking out the system
if ignition is not established or flame is lost.
. What is the most important first step before servicing an oil-fired appliance?
A. Replace the nozzle.
B. Disconnect electrical power and confirm safe shutdown.
C. Open the oil supply valve fully.
D. Adjust the air shutter to maximum.
🟢 Correct answer: B
🔴 RATIONALE: Safe isolation of electrical power and shutdown of the appliance is the first priority before
any service work begins.
. What is the main purpose of the burner nozzle?
A. To atomize oil into a fine spray for efficient combustion.
B. To regulate flue gas temperature.
C. To store fuel for rapid firing.
D. To control chimney pressure.
🟢 Correct answer: A
🔴 RATIONALE: The nozzle breaks fuel oil into a fine spray so it can mix properly with air and burn
efficiently.
, . An oil burner repeatedly locks out shortly after start-up. What is the most likely area to inspect first?
A. Thermostat anticipator.
B. Flame sensing and ignition system.
C. House circuit breaker size.
D. Humidifier bypass damper.
🟢 Correct answer: B
🔴 RATIONALE: Repeated lockout soon after start-up commonly indicates ignition, flame-proving, or
combustion-related failure.
. Which condition most directly causes smoke from an oil burner?
A. Excessive combustion air.
B. A clean nozzle with proper draft.
C. Incomplete combustion from poor air-fuel mixing.
D. Low room humidity.
🟢 Correct answer: C
🔴 RATIONALE: Smoke is usually produced when combustion is incomplete due to insufficient air, poor
atomization, or improper burner setup.
. What is the purpose of the cad cell in a primary control system?
A. It senses flame presence through light.
B. It measures oil pressure.
C. It opens the oil valve mechanically.
D. It raises line voltage to the ignition transformer.
🟢 Correct answer: A
🔴 RATIONALE: The cad cell is a flame sensor that verifies flame by detecting light intensity in the
combustion chamber.
QUESTIONS AND CORRECT ANSWERS (VERIFIED ANSWERS) PLUS RATIONALES 2026 Q&A
| INSTANT DOWNLOAD PDF.
Core Domains
Fuel oil combustion theory.
Oil burner components and controls.
Installation and servicing procedures.
Troubleshooting and diagnostics.
Electrical circuits and safety controls.
Venting, draft, and combustion air.
Codes, standards, and regulatory compliance.
Occupational health, safety, and professional practice.
Introduction
,This assessment is designed to measure the knowledge and decision-making expected of an Ontario Oil
Burner Technician 2 candidate. It covers theory, practical application, safety, regulatory compliance, and
workplace judgment in situations that reflect real servicing and installation work. Questions combine
multiple-choice knowledge checks with scenario-based problems to assess how well a technician can select
safe, code-compliant, and effective actions in the field. The format emphasizes applied understanding,
diagnostic reasoning, and professional responsibility. Each item is written to support exam preparation by
reinforcing correct procedures, common faults, and the standards expected in fuel-burning appliance work.
Section One
,. Which statement best describes the primary function of an oil burner primary control?
A. It measures room temperature and starts the blower.
B. It regulates domestic hot water supply pressure.
C. It controls fuel delivery and shuts down on flame failure.
D. It increases chimney draft during start-up.
🟢 Correct answer: C
🔴 RATIONALE: The primary control supervises burner operation, proving flame and locking out the system
if ignition is not established or flame is lost.
. What is the most important first step before servicing an oil-fired appliance?
A. Replace the nozzle.
B. Disconnect electrical power and confirm safe shutdown.
C. Open the oil supply valve fully.
D. Adjust the air shutter to maximum.
🟢 Correct answer: B
🔴 RATIONALE: Safe isolation of electrical power and shutdown of the appliance is the first priority before
any service work begins.
. What is the main purpose of the burner nozzle?
A. To atomize oil into a fine spray for efficient combustion.
B. To regulate flue gas temperature.
C. To store fuel for rapid firing.
D. To control chimney pressure.
🟢 Correct answer: A
🔴 RATIONALE: The nozzle breaks fuel oil into a fine spray so it can mix properly with air and burn
efficiently.
, . An oil burner repeatedly locks out shortly after start-up. What is the most likely area to inspect first?
A. Thermostat anticipator.
B. Flame sensing and ignition system.
C. House circuit breaker size.
D. Humidifier bypass damper.
🟢 Correct answer: B
🔴 RATIONALE: Repeated lockout soon after start-up commonly indicates ignition, flame-proving, or
combustion-related failure.
. Which condition most directly causes smoke from an oil burner?
A. Excessive combustion air.
B. A clean nozzle with proper draft.
C. Incomplete combustion from poor air-fuel mixing.
D. Low room humidity.
🟢 Correct answer: C
🔴 RATIONALE: Smoke is usually produced when combustion is incomplete due to insufficient air, poor
atomization, or improper burner setup.
. What is the purpose of the cad cell in a primary control system?
A. It senses flame presence through light.
B. It measures oil pressure.
C. It opens the oil valve mechanically.
D. It raises line voltage to the ignition transformer.
🟢 Correct answer: A
🔴 RATIONALE: The cad cell is a flame sensor that verifies flame by detecting light intensity in the
combustion chamber.
