MODULEX EXT 321, 481, 641, 802, 962, 1123 BOILERS
Installation, Operation & Maintenance Manual
OMM-0087_0F AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 Page 119 of 146
GF-143 Phone: 800-526-0288 07/13/15
Table 6-4: BMM Fault Codes (Continued)
E 14
Check return sensor or
wiring.
E 15
temperature
protection.
Flow
temperature -
Return
Temperature >
Water Δ-Temp
Protection +
turned OFF
and Pump ON
at maximum
speed.
installation.
when Δ-
temperature <
Water Δ-Temp
Protection.
E 16
frozen. Flow
sensor
temperature is
inhibited. Pump
runs for 5 min
at max speed.
Carefully defrost boiler.
when flow sensor is
greater than 41°F.
E 20
detected after
burner is OFF.
inhibited.
Disconnect gas valve wire
from BMM. If failure goes
away, check wiring or
change BMM. If failure
remains, check or change
reset switch or
cycle power.
E 22
burner after fan
started for 30
seconds.
after 60 second
delay and
failure remains
until a
successful
burner
operation.
supply voltage and fan
wiring. If OK, try another
fan. If still not working,
change the BMM.
If fan is not stopped, check
the exhaust gas outlet for
blockage. If OK, check the
air pressure switch wiring. If
still not working, try another
air pressure switch. If still
not working, change the
UAL
E 23
pressure switch
doesn't switch
off.
inhibited.
Disconnect the air proving
switch. If problem goes
away, install a new switch.
If not, check the wiring. If
wiring is OK, change BMM.