As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PERFORMING AD ON THE AFFECTED HEATER IAW SB A-103. UPON COMPLETION OF THE PRESSURE DECAY TEST, PERFORMED AND OPS TEST OF AIR PRESSURE SWITCH. FOUND THE SWITCH FAILED IN A CONTACT CLOSED CONDITION. UPON REMOVING THE SWITCH, NOTICED IT WAS A 94E42-1 SWITCH. THIS IS THE PN THAT (ACCORDING TO SB A-103) HAS BEEN REDESIGNED TO ELIMINATE THE NOTED FAILURE MODE OF OLD SWITCH AND UPGRADE OLDER TECHNOLOGY HEATERS.(K)