Based on the Red Seal Oil Heat System Technician exam blueprint: fuel storage and supply, appliances, venting and combustion air, electrical systems, and maintenance and diagnosis
Practice on the go and jump straight back to where you left off.
About the certification
Oil Heat System Technician is a Red Seal trade. These technicians install, retrofit, maintain, diagnose and repair oil-fired heating appliances, fuel storage and supply systems, venting, combustion air and the electrical controls that run them. The Red Seal Interprovincial Examination is the national exam for the trade. In Ontario, oil burner technicians are certified through TSSA (OBT-1, OBT-2 and OBT-3) instead, so this quiz follows the national Red Seal standard and not Ontario certificate scopes.
The Red Seal exam has 110 multiple-choice questions in 6 major work activities: common occupational skills (7 questions), fuel supply and storage systems (20), oil-fired heating systems (23), venting, combustion air and make-up air (17), electrical and electronic systems (22), and maintenance, diagnosis, repair and removal (21). Between 65 and 75% of the questions test procedural knowledge and application, 10 to 20% knowledge and recall, and 10 to 20% critical thinking. The pass mark is 70% and the writing time is four hours. A short formula sheet is provided with the exam.
ExamHub's free practice quiz has 167 original questions weighted to those activities, with an explanation and a source for every answer. They are written from the Red Seal standard, NRCan's Heating with Oil guide, the burner, control, nozzle and tank manufacturers' instructions, and public regulator documents. The CSA B139 installation code is a paid standard that SkilledTradesBC lists as supplied at the exam sitting, so ExamHub does not reproduce it: the questions ask what the technician does and why.
Sources: the Red Seal Oil Heat System Technician exam information and the Red Seal Exam Preparation Guide. See how ExamHub checks its questions.
Exam details as of October 2026.
| Item | Red Seal exam | ExamHub bank |
|---|---|---|
| Format | 110 multiple-choice questions | 167 multiple-choice questions |
| Pass mark | 70% | 70% (Test Mode) |
| Time | 4 hours | Up to 4 hours (Test Mode) |
| A Common occupational skills | 7 | 11 |
| B Fuel supply and storage systems | 20 | 30 |
| C Oil-fired heating systems | 23 | 35 |
| D Venting, combustion air and make-up air | 17 | 26 |
| E Electrical and electronic systems | 22 | 33 |
| F Maintenance, diagnosis, repair and removal | 21 | 32 |
What's covered
Categories group the 18 Red Seal exam tasks, weighted like the real exam.
Try a few
Five sample questions from the question bank, with the answer and explanation.
Why: Slope is rise divided by run. The tank must fall 10 mm for every 500 mm of length, so over 1,400 mm the minimum drop toward the outlet is 1,400 / 500 x 10 = 28 mm. Using 1,400 / 1,000 x 10 gives 14 mm, and rounding the run up to 1,750 mm would give 35 mm. The slope keeps water and sludge moving toward the outlet end, where they can be seen and removed.
Why: For an appliance in a confined space the manufacturer requires two permanent openings, one near the top and one near the bottom of the enclosure. Each must have free area of not less than 1 sq in. per 1,000 Btu/h of the total input of all appliances in the enclosure: 150,000 / 1,000 = 150 sq in. each. The 37.5 and 75 sq in. values correspond to 1 sq in. per 4,000 and per 2,000 Btu/h, which are for outdoor-air arrangements.
Why: Nozzle flow changes with the square root of the pressure ratio: 0.85 x square root of (140 / 100) = 0.85 x 1.183 = 1.01 gph, which matches the manufacturer's flow chart. Multiplying by the pressure ratio itself (1.4) gives 1.19 gph, dividing by the square root gives 0.72 gph, and the stamped 0.85 gph applies only at 100 psi.
Why: In the cad cell resistance check, one flash means 0-400 ohms, two flashes 400-800 ohms, three flashes 800-1,600 ohms and four flashes above 1,600 ohms. For proper operation the resistance must be below 1,600 ohms, so four flashes is a fault: the lens is cleaned, the view of the flame checked, or the cell replaced. Restricted lockout is shown by a different flash pattern.
Why: The trace-of-smoke point is the reference. The air is then increased until the CO2 is 1.5 to 2 percentage points lower: from 13.5% to 11.5% (about 12%). The smoke level is rechecked and should be zero, which gives a margin of reserve air for variable conditions. Leaving the burner at a trace of smoke leaves no margin; CO2 cannot rise as the air is increased.
FAQ
The Red Seal exam has 110 multiple-choice questions with four options each. ExamHub's bank has 167 questions, and Test Mode draws a 110-question timed simulation.
The Red Seal pass mark is 70% and the writing time is four hours. ExamHub's Test Mode uses the same 70% pass mark and up to 240 minutes.
6 major work activities: common occupational skills (7 questions), fuel supply and storage systems (20), oil-fired heating systems (23), venting, combustion air and make-up air (17), electrical and electronic systems (22), and maintenance, diagnosis, repair and removal (21).
No. SkilledTradesBC lists the CSA B139 Series 24 code book as supplied at the exam sitting. ExamHub does not reproduce the code; its questions rest on public documents such as NRCan's guide and manufacturers' instructions and ask what to do and why.
No. In Ontario the credential is the TSSA oil burner technician certificate (OBT-1, OBT-2 or OBT-3). This quiz follows the national Red Seal standard, so it does not test Ontario certificate scopes or Ontario amendments to the code.
No. These are original practice questions written from the Red Seal standard and free public sources. They are not copies of exam questions.