Where should the discharge piping serving a temperature and pressure relief valve of a water heater terminate?

The discharge piping serving a temperature and pressure relief valve of a water heater should terminate to the floor or outdoors to ensure safety and proper function. This configuration is important because the purpose of the temperature and pressure relief valve is to release excess pressure and temperature from the water heater to prevent potential hazards, such as an explosion.

By directing the discharge to the floor when indoors, you allow any escaping water to drain away safely without causing structural damage or creating hazards. If the discharge pipe were to terminate outdoors, it would enable the safe release of hot water without causing injury to people nearby and would also prevent water from pooling in indoor areas.

Furthermore, terminating the discharge piping inappropriately, such as into a sink or above the roof, could pose risks, such as backflow or improper pressure release, both of which defeat the purpose of the safety mechanism provided by the relief valve. Hence, the safest and most compliant practice, according to plumbing codes, is to ensure that the discharge piping either ends on the floor or, if outdoors, is positioned away from any areas where people could be harmed.