MODULEX EXT 321, 481, 641, 802, 962, 1123 BOILERS
Installation, Operation & Maintenance Manual
Page 116 of 146 AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 OMM-0087_0F
07/13/15 Phone: 800-526-0288 GF-143
Table 6-2: E8 Controller Fault Codes (Continued)
FAULT CODE FAULT DESCRIPTION
Communication Fault
E 90
E8: BUS addresses 0 and 1. The BUS codes 0 and 1 cannot be used at
the same time.
E 91
E8: BUS code occupied. The set BUS code is already used by another
appliance.
Internal Fault
E 81
E8: EEPROM fault. The invalid value has been replaced by the standard
value.