It is strictly advised to use CPVC pipes and CPVC fittings in all internal plumbing for hot and cold water lines. In cases of non-adherence to this advisory, there have been instances of non-return valve failure or pressure differential in hot and cold-water lines due to which hot water has entered the cold line. If the cold-water line pipe is not temperature resistant, the supply could leak or burst causing huge loss and inconvenience to the customer.