As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE PROBLEM THAT WE ARE HAVING IS WITH THE HEATER FUEL PRESSURE REGULATORS P/N A23D04-7.5 THEY START LEAKING FUEL AROUND THE HOUSEING. THE FIRST ONE STARTED LEAKING AFTER 180.9 HOURS OF HEATER OPERATION. INSTALLED NEW IN STOCK UNIT, AND IT LEAKED ON FIRST TEST FIRING. WE ALSO JUST HAD ANOTHER UNIT START LEAKING ON ONE OF OUR OTHER PIPER NAVIJO HEATER. THIS UNIT HAD 834.1 HEATER HOURS ON IT WHEN IT STARTED LEAKING.