306A Study Guide 2026
Everything you need to pass the 306A exam in one place: the exam format, every topic to study, real practice questions with explanations, flashcards, and full-length practice tests. Free, no sign-up needed.
📋 306A Exam Format at a Glance
📚 306A Topics to Study (39)
✍️ Sample 306A Questions & Answers
1. What is the minimum capacity of a residential water heater for a family of four?
A 190-litre (50-gallon) water heater is generally recommended as the minimum for a family of four to provide adequate hot water for multiple bathrooms, laundry, and kitchen use during peak demand periods.
2. What pipe material is most commonly used for interior residential natural gas piping in Canada?
Black steel (iron) pipe with threaded fittings is the most common material for interior natural gas piping. It is strong, durable, and approved for gas service. Galvanized pipe is not recommended because the zinc coating can flake off and clog gas valve orifices.
3. When installing a kitchen sink, what type of strainer assembly is typically used?
A basket strainer assembly with plumber's putty or silicone seal, a rubber gasket, and a locknut is the standard installation for kitchen sinks. The removable basket catches food debris to prevent drain blockages.
4. Which joining method is NOT rated for pressurized copper water supply piping and therefore cannot be used on supply lines?
No-hub couplings are designed for low-pressure gravity drain piping and are not rated for the working pressures found in domestic water supply systems.
5. What valve type is NOT acceptable as an isolation valve on a water supply branch because it restricts flow?
A globe valve creates significant flow restriction due to its internal design, which forces water to change direction through the valve body. Ball and gate valves provide full-port (unrestricted) flow and are preferred for isolation.
6. After cutting rigid PVC pipe with a hacksaw for a solvent-cemented joint, what must be done to the pipe end before applying primer?
Deburring and chamfering removes sharp edges that would scrape cement from socket walls and ensures the pipe seats to full depth for a strong solvent bond.