Massachusetts Plumbers Journeyman Practice Exam

How close can PEX tubing be installed to any connection to a direct fired water heater or boiler?

1. 12 inches

2. 18 inches

3. 24 inches

4. 30 inches

The correct answer is: 24 inches

The correct distance for installing PEX tubing in relation to a connection to a direct fired water heater or boiler is 24 inches. This requirement is in place to ensure safety and maintain the integrity of the PEX material, which can be sensitive to high temperatures. Direct fired water heaters and boilers produce significant heat, and maintaining this distance helps to prevent potential degradation or failure of the PEX. Other distances, while they may provide some level of clearance, do not meet the specific safety and performance standards that protect the plumbing system and ensure safe operation of the water heater or boiler. The 24-inch guideline offers an appropriate balance, adhering to code requirements and industry best practices.