As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKE OFF, L DUCT PRESS READ ZERO WITH # 1 ENG BLEED SWITCH ON. (PRESS READ NORMAL WHEN ISOLATION VALVE SWITCH POS TO "OPEN"). GROUNDED - YES. DIVERSION TIME 26 MINUTES. PERFORMED FIM PROCEDURE REF B737-800 FIM 36-10 TASK 805, REMOVED & REPLACED 450 DEGREE THERMOSTAT REF B737-800 AMM 36-11-05. PERFORMED ENGINE RUN-UP. SYSTEM OP CHECK NORMAL.