As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LEFT FWD WINDOW HEAT AMBER OVERHEAT ILLUMINATED ON GROUND. ACCOMPLISHED QRH. RESTORED TO NORMAL OPERATION. GROUNDED - YES. PERFORMED WHCU SYS TEST ON #1 & #1 CONTROLLER REF B737-9 AMM 30-41-11-710-801. BOTH SYS TEST PASSED W/ NO CURRENT FAULTS NOTED AT THIS TIME.