Working on old Capitol Hill homes I commonly find problems with HVAC Systems condensate discharge lines. Even when I find them currently functioning properly, they are often built out of code. The common code problems I find with HVAC condensate discharge lines follows:
1. Sizing – the building code requires 3/4″ minimum diameter piping to be used.
2. Materials – the building code allows for copper, CPVC, PVC, and polyethylene pipe to be used for condensate discharge drains.
3. Interference with other systems – condensate discharge drains are not permitted to enter into overflow pans, or drains for other systems.
Following the code, allows pipes to dischsrge with lower tendency for backup and destruction from flooding caused by backups.