As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) DURING CLIMB THROUGH FL 130 CREW ENCOUNTERED PRESSURIZATION PROBLEM. AT ONE POINT PRESSURIZATION SEEMED STABILIZED BUT CABIN STARTED TO RISE AGAIN. AIRCRAFT RETURNED TO FIELD. MAINTENANCE REPLACED THE LH NAPRSOV DUE TO FAULT CODES 1006 & 1007. PRESSURIZATION SYSTEM WAS CHECKED FOR OPERATION & AIRCRAFT RETURNED TO SERVICE. NO FURTHER PROBLEM.