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 REMAINED ILLUMINATED BRIGHT BLUE WITH TAI AMBER LIGHT DURING FLIGHT WITH ENGINE ANTI-ICE SWITCH TURNED ON. ACFT GROUNDED. REPLACED NR 1 ENGINE ANTI-ICE VALVE, OPS CK FAILED. R & R VALVE AGAIN REF MM 30-21-11. LEAK & OPS CK GOOD REF SAME. GROUND VERIFICATION SUCCESSFUL.