As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
NR 1 COWL VALVE OPEN LIGHT REMAIN BRIGHT BLUE WHEN NR 1 ENGINE ANTI -ICE SWITCH IS TURNED ON. NR 1 COWL VALVE OPEN LIGHT EXTINGUISHES WHEN NR 1 ENGINE ANTI-ICE SWITCH IS TURNED OFF. ACFT GROUNDED. REMOVED AND REPLACED THE NR 1 COWL ANTI-ICING VALVE (TAI) IAW AMM 30-21-11/401. OPS AND LEAK CHECKED NORMAL.