What was found
CUSTOMER WAS CHECKING HEATER IAW AD96-20-07 EVEN THOUGH HE WASN’T REQUIRED TO DO SO, AND FOUND THE COMBUSTION AIR PRESSURE SWITCH CLOSED AT ALL TIMES. THIS IS A NORMALLY OPEN SWITCH. CUSTOMER INFORMED US THAT THE HEATER HAS 76 HRS. TT. THIS WAS A WARRANTY CLAIM. UPON RECEIPT OF THE DEFECTIVE SWITCH, CONCLUDED THAT THE SWITCH WAS CLOSED AT ALL TIMES. THIS SWITCH (AND HEATER) IS NOT REQUIRED TO BE TESTED IAW AD 96-20-07. THE HEATER, THIS SWITCH IS INSTALLED ON IS PN FR90D38-1EL AND WAS BUILT IN FEBRUARY 2002. TO PREVENT RECURRENCE, HAVE OPERATORS CHECK HEATERS AND SWITCHES WITH A SB OR AD. (K)