What is the maximum height the TPR discharge pipe should terminate above the floor or waste receptor?

The maximum height that a Temperature and Pressure Relief (TPR) discharge pipe should terminate above the floor or waste receptor is 6 inches. This specification is important for several reasons.

Firstly, it ensures that any water discharged from the TPR valve, which is a safety feature designed to prevent excessive pressure and temperature in a water heater, does not create a hazardous situation. If the termination point is too high, there may be a risk of injury from scalding hot water or steam if a discharge event occurs. The 6-inch height provides a reasonable buffer that minimizes the risk of water spraying out at dangerous heights while still allowing for effective drainage away from the unit.

Secondly, the termination height is designed to ensure proper drainage of discharge water. A 6-inch termination allows for enough clearance to guide water safely into a drain or receptor, promoting proper drainage and preventing potential backflow issues.

By adhering to this standard, compliance with plumbing codes and safety regulations is ensured, contributing to the overall safety and functionality of the water heating system.