Oil Burner Technician 3 (OBT-3): O. Reg. 215/01 scope and supervision, O. Reg. 213/01, the B139 Ontario CAD, tanks and piping, burners and nozzles, controls, venting and combustion analysis
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About the certification
In Ontario, work on oil-fired appliances and their tanks is regulated by the Technical Standards and Safety Authority (TSSA). The Oil Burner Technician 3 (OBT-3) is the entry-level certificate: under O. Reg. 215/01, s. 41, an OBT-3 holder does listed functions under general supervision on an appliance of not more than 2 U.S. gallons per hour, or any function of the supervisor’s certificate under direct supervision, and may never perform the initial activation of a new appliance.
The TSSA pass mark is 75%. TSSA does not publish the number of questions or the time allowed on the OBT-3 examination, so ExamHub’s Test Mode draws 100 questions in 120 minutes as a practice length. TSSA document FS-280-26 adopts the CSA B139 Series-24 codes with Ontario amendments.
ExamHub’s free OBT-3 practice test has 150 original questions, each with an explanation and a free public source.
| Certificate | OBT-3 (Oil Burner Technician 3) |
|---|---|
| Regulator | TSSA (Ontario) |
| Pass mark | 75% (official) |
| Official question count and time | Not published by TSSA |
| ExamHub Test Mode | 100 questions, 120 minutes (practice length) |
| Question bank | 150 original questions |
Sources and last reviewed: TSSA OBT-3 curriculum (January 2025), O. Reg. 215/01 and 213/01 on e-Laws, TSSA Fuel Oil Code Adoption Document amendment FS-280-26. Last reviewed October 2026.
To see how ExamHub writes and checks questions, read About ExamHub.
What’s covered
Categories follow the OBT-3 curriculum theory modules: regulations, fuel oil and safety, tanks and piping, appliances and burners, electricity, controls, venting and combustion.
Try a few
Five sample questions from the question bank, with the answer and explanation.
Why: O. Reg. 215/01, s. 41(1) lists the OBT-3 general-supervision functions on an appliance with an input rate not greater than 2 U.S. gallons per hour (gph). The 7 U.S. gph figure is the OBT-2 limit (s. 40(1)); an OBT-1 has no input limit in s. 39.
Why: Clause 6.2.1.3 as added by FS-280-26 requires steel tanks to have (a) double-bottom construction with a minimum 50 mm coverage above the bottom and a visual interstitial monitoring device, (b) non-combustible secondary containment, or (c) a minimum 300 degree integral secondary containment with monitoring of the interstitial space.
Why: The curriculum says the motor drives the pump through a pump coupling designed to break if the pump seizes, which protects the motor. The pump also provides regulated nozzle pressure and a clean cut-in and cut-out of oil flow.
Why: On flame loss the R7184 shuts down, enters a 60 second recycle delay and repeats the ignition sequence; limited recycle locks the control out after three flame losses so that repeated cycling on poor combustion is prevented.
Why: Beckett's procedure: Step 1 adjust the air until a trace of smoke is achieved, step 2 measure CO2 (or O2) at the trace-smoke point, step 3 increase air to reduce CO2 by 1 to 2 percentage points, and step 4 recheck the smoke level, which should be zero.
FAQ
No. This is unofficial study practice written from free public sources: the TSSA OBT-3 curriculum (revised January 2025), Ontario e-Laws (O. Reg. 215/01, O. Reg. 213/01, the Technical Standards and Safety Act, 2000), the TSSA Fuel Oil Code Adoption Document amendment FS-280-26, burner and control manufacturers’ instructions and Natural Resources Canada guidance. It does not reproduce the licensed CSA B139 text or real exam questions.
TSSA does not publish the number of questions or the time allowed on the OBT-3 examination. The pass mark is 75% (TSSA Gas Technician/Oil Burner Technician Policies and Procedures, section 6).
Test Mode draws 100 questions with a 75% pass mark. The 75% pass mark is official (TSSA Policies and Procedures, section 6). Because TSSA does not publish the question count or time, 100 questions in 120 minutes is ExamHub’s practice length, not the official length.
Under O. Reg. 215/01, s. 41, an OBT-3 holder working under general supervision of an OBT-2 or OBT-1 holder, with essential skills demonstrated and signed off, may on an appliance of not more than 2 U.S. gallons per hour do a comprehensive inspection, clean, remove and adjust a flue pipe or draft regulator, clean, lubricate and maintain an appliance, do annual-maintenance tests and adjustments, install, activate or bleed oil piping under 2 1/2 inches, and reactivate a previously installed appliance. An OBT-3 may never perform the initial activation of a new or newly converted appliance.
TSSA’s Fuel Oil Code Adoption Document amendment FS-280-26 (dated 2 April 2026) adopts the CSA B139 Series-24 installation codes with Ontario amendments, alongside O. Reg. 213/01 (Fuel Oil). ExamHub cites only free public text, including what the TSSA document reproduces, and never reproduces paywalled CSA content.
They are original practice questions written by ExamHub, each with an explanation and a named public source, and mapped to the OBT-3 curriculum modules. They are not copies of exam questions.