As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER DEPARTURE MIDDLE LEFT WING DEICE BOOT FAILED TWICE. RETURNED TO SFO. OPERATED LEADING EDGE DEICE THROUGH SEVERAL CYCLES, COULD NOT DUPLICATE PROBLEM. SWAPPED LEFT AND RIGHT MIDDLE BOOT DEICE PRESSURE SWITCHES FOR TROUBLESHOOTING, OPS CHECK GOOD.