As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE L2 WINDOW OVERHEAT LIGHT IS ILLUMINATED. GROUNDED - YES. PERFORMED WHCU BITE AND FOUND SEVERAL WINDOW SENSOR FAULTS LOGGED. FURTHER TROUBLESHOOTING FAULT COULD NOT BE REPRODUCED. PERFORMEDB737-900 AMM TASK 30-41-11-710-801 (WHCU SYSTEM TEST) OPS CHECK PASSED.