As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PITOT HEAT 1 INOP ON THE GROUND DURING PREFLIGHT. DEFERRED PITOT HEAT TO GET IT HOME. MX FOUND PITOT HEAT SWITCH WITH HEAT DAMAGE AROUND PINS 2, 5, AND 6. WITH CORRESPONDING HEAT DAMAGE ON SWITCH CONNECTOR AND WIRING TERMINALS. REPLACED SWITCH AND OPS CHECK GOOD. THIS FAILURE IS COMMON AND WE HAVE SEEN THE SWITCH BODY WITH A HOLE MELTED THROUGH THE SIDEWALL.