As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CLIMB LEFT FWD WINDOW OVERHEAT LIGHT ILLUMINATED. RAN QRH. CAUTION LIGHT REMAINED ILLUMINATED. GROUNDED - YES. TROUBLESHOT L/H FWD WINDOW OVERHEAT LIGHT PER B737-900 FIM 30-41 TASK 801. COULD NOT DUPLICATE FAULT. FAULT L/H FWD WINDOW D WINDOW OVERHEAT INTERMITTENT. PERFORMED OPERATIONAL TEST OF WINDOW HEAT CONTROL UNIT #2 PER B737-900 AMM TASK 30-41-11-710-801. OPS CHECK GOOD. NO FAULTS FOUND.