As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LEFT SIDE WINDOW HEAT OVERHEAT LIGHT ILLUMINATED IN FLIGHT. LIGHT TURNED OFF AFTER QRH CHECKLIST POWER CYCLE. DID NOT RE-ILLUMINATE. GROUNDED - YES. RELOCATED TAP FROM H16 TO H15 TERMINAL 2 OF TB5016 REF B737-900 WDM 30-41-12 PG.2 . REMOVED AND REPLACED CAPT L/H #2 OPENABLE WINDOW REF B737-900 AMM 52-12-11. NO LEAKS NOTED.