G3 Controls and Ignition Systems: What's Tested and How to Study It
Pilots, ignition types, safety shut-off, thermocouples and flame supervision.
The smallest topic by question count and one of the most precisely worded. Pilot types in particular are defined terms, and the exam expects the definition rather than a description.
What does the G3 exam test on Controls and Ignition Systems?
Pilots, ignition types, safety shut-off, thermocouples and flame supervision. The question bank holds 57 questions in this area,
out of 1,184 across the whole syllabus.
Continuous, intermittent, interrupted and expanding pilots
Thermocouples and thermopiles, and their expected readings
Direct spark and hot surface ignition
Flame supervision and safety shut-off
Trial for ignition timing
Gas valves and pressure regulation
How should you study Controls and Ignition Systems for the G3 exam?
Learn the pilot definitions word for word. The distinctions are small — whether the pilot burns with turndown, whether it is cut at the end of trial for ignition — and the answers hinge on exactly those phrases.
Sample G3 exam questions on Controls and Ignition Systems
Five real questions from this topic, with the answers shown. The app holds
57 in this area alone, out of 1,184 across the whole syllabus.
What activates a flame rollout switch?
Loss of combustion air
✓ A rise in temperature near the burner area
High limit switch failure
A drop in gas pressure
What is a thermopile (powerpile) used for in gas appliances?
To measure gas pressure
To detect carbon monoxide
✓ To power both the combustion safety and control circuits
To regulate the gas flow rate
Which expression best describes a control intended to prevent an unsafe condition of temperature, pressure or liquid level?
High/low pressure switch
Roll out switch
Fan control
✓ Safety limit control
'Yellow tipping' in a burner is an indication of:
✓ Too little primary air
Too much secondary air
Too little secondary air
Too much primary air
What is the expected 'open' reading on a thermocouple?