As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
HEATER INSPECTION REVEALED OVERHEAT FUSE WAS OF THE CORRECT AMPERAGE, BUT WAS OF THE TIME DELAY (SLOW BLOW) TYPE FUSE. HEAT WAS APPLIED TO THE OVERHEAT PROBE AND 45 SECONDS AFTER ACTUATION OF THE PROBE, THE FUSE HAD NOT BLOWN. THE FUSE WAS REPLACED WITH THE CORRECT QUICK ACTING TYPE AND IT BLEW AFTER APPROXIMATELY 10 SECONDS OF PROBE ACTUATION.