As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WINDOW OVERHEAT WARNING LIGHT CAME ON ENROUTE. RAN QRH 3.6 PROCEDURE AND OVERHEAT LIGHT STAYED ON. L SIDE WINDOW. GROUNDED - YES. PRIMARY SENSOR LOOP IN WINDOW READS OPEN. SWAPPED TO SPARE SENSOR LOOP. ETOPS GROUND FUNCTIONAL CHECK OPS CHECK GOOD IAW B737-800 AMM 30-41-11-710-801.