As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FOLLOW-UP TO RECENT HISTORY OF NR 1 ENGINE COWL ANTI ICE VALVE OPEN LIGHT STAYING ON BRIGHT. GROUNDED-YES. REMOVED AND REPLACED NR 1 ENGINE ANTI-ICE VALVE WITH NEW, PER B737-800 AMM 30-21-11. LEAK CHECK AND OPERATIONS CHECK GOOD, PER AMM 30-21-11.