Why is a relief-valve pipe terminating into a water leak catch pan not permitted?

A relief-valve pipe should terminate into a proper indirect waste receptor to ensure that any discharge is handled appropriately without creating health hazards or code violations. When a relief-valve pipe ends in a water leak catch pan, it lacks the necessary drainage provisions found in a true indirect waste receptor.

An indirect waste receptor is designed to receive waste or discharge from a plumbing system and direct it safely to the drainage system without the possibility of backflow or contamination. A catch pan does not provide this necessary drainage or protection, thus potentially leading to overflow issues and creating an environment where hazardous materials could accumulate.

If the relief valve discharges into a pan without adequate drainage, it may not only overflow but might also lead to pooling of water, which could cause both property damage and a risk of slippage. This situation is clearly not compliant with plumbing codes and standards, which require that such systems are set up to handle potential discharges safely and effectively. Therefore, terminating a relief-valve pipe in a catch pan is not permitted due to its failure to function as an appropriate waste receptor.