ONTARIO GAS TECHNICIAN 1 (G1) CERTIFICATION EXAM 2026 COMPLETE QUESTIONS AND DETAILED SOLUTIONS LATEST UPDATE THIS YEAR JUST RELEASED

ONTARIO GAS TECHNICIAN 1 (G1)
CERTIFICATION EXAM 2026 COMPLETE
QUESTIONS AND DETAILED SOLUTIONS
LATEST UPDATE THIS YEAR JUST
RELEASED



Ontario Gas Technician 1 (G1) Examination — Actual
Exam Coverage
The Ontario Gas Technician 1 (G1) certification is the
highest gas technician trade qualification regulated by the
Technical Standards and Safety Authority (TSSA). The
examination evaluates advanced knowledge required to
install, service, commission, troubleshoot, supervise, and
approve natural gas and propane systems in commercial,
industrial, and large institutional environments.


Exam coverage


 Gas laws, combustion, and fuel properties  Ontario gas
regulations and CSA code requirements 
Commercial/industrial appliance installation  Pipe sizing

,and gas supply calculations  Pressure regulators and gas
trains  Boiler, burner, and furnace operations  Venting
and combustion air systems  Electrical troubleshooting
and control circuits  Flame safeguard programming and
sequencing  Combustion analysis and efficiency
optimization  Leak testing, purging, and commissioning 
Safety systems and emergency procedures 
Troubleshooting ignition and burner failures  CO testing
and hazardous condition response  Preventive
maintenance and documentation




Question 1
A commercial boiler repeatedly locks out approximately
five seconds after ignition despite stable inlet gas pressure
readings and proper ignition spark generation. Which
condition is the MOST likely cause?
A. Excess manifold pressure preventing flame stabilization
B. Faulty flame rectification sensing insufficient microamp
signal
C. Undersized vent connector increasing draft excessively
D. Defective transformer secondary winding overheating
immediately

,Answer: B. Faulty flame rectification sensing insufficient
microamp signal
Rationale:
Flame safeguard systems rely on flame rectification to
prove burner flame presence. If the microamp signal is
insufficient, the control interprets the condition as flame
failure and shuts down the burner shortly after ignition
despite successful flame establishment.


Question 2
During combustion analysis of a high-efficiency
condensing boiler, a technician records elevated carbon
monoxide levels and reduced oxygen percentages. Which
adjustment should be performed FIRST?
A. Increase vent connector diameter
B. Replace condensate neutralizer
C. Reduce manifold gas pressure slightly
D. Increase circulating pump speed immediately
Answer: C. Reduce manifold gas pressure slightly
Rationale:
Elevated CO and low oxygen indicate an overly rich
combustion mixture. Reducing manifold gas pressure
helps restore the proper air-fuel ratio and improves

, combustion efficiency while lowering carbon monoxide
production.


Question 3
A gas technician discovers a steam boiler low-water cutoff
fails to interrupt burner operation during testing. What is
the MOST appropriate immediate action?
A. Continue operation while monitoring water level
manually
B. Replace the pressure relief valve first
C. Shut down and disable the boiler immediately
D. Increase feedwater pressure temporarily
Answer: C. Shut down and disable the boiler immediately
Rationale:
A failed low-water cutoff creates a severe safety hazard
that could cause boiler dry-firing and catastrophic vessel
failure. The boiler must be removed from operation until
repairs are completed.


Question 4
A commercial rooftop heating unit exhibits delayed
ignition accompanied by loud ignition rumbling. Which
condition MOST likely contributes to this problem?