Watts Aerco Modulex MLX EXT 1530 - Page 112

Modulex EXT Commercial Series Boilers User Manual
CHAPTER 7: Troubleshooting
Page 112 of 144 AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 OMM-0095_0H
09/15/2017 Phone: 800-526-0288 GF-139
TABLE 7-2: E8 Controller Fault Codes (Continued)
CODE DESCRIPTION EFFECT CORRECTION RESET
E 16
Boiler body
temperature very low:
Ice forming risk
Boiler will not run.
Pump runs for 5
minutes.
Carefully defrost boiler.
AUTOMATIC - when
sensor is >41°F
E 20
Flame signal detected
after burner is OFF.
Boiler will not run.
Allow flame rod to cool.
Possibly replace flame rod.
MANUAL - Push reset
switch or cycle power.
E 24
Modulating fan speed
failure: failed to reach
the correct speed
within 30 seconds
from starting of
burner ignition cycle.
Boiler will not
ignite.
Check Expert HS fan speed
settings. May require a new
blower.
AUTOMATIC
E 26
Modulating fan speed
failure: failed to stop
within 30 seconds
from end of operation
Boiler will not
ignite.
Check Expert HS fan speed
settings. Check fan wiring. May
require a new blower.
AUTOMATIC
E 28
Common chimney
obstruction.
Boiler will not run.
Check pressure in chimney
during operation. Ensure hoses
to pressure switches are clear.
MANUAL
E29
Water inside exhaust
chamber.
Boiler shuts off.
Check for backed up
condensate in exhaust
manifold. Clean p-trap and
condensate drain line. Check
float sensor in exhaust
manifold for proper operation.
AUTOMATIC
E 30
Alteration of the
operating parameters
caused by EMC
disturbances.
Boiler will not run.
Pump runs for 5
minutes.
Re-program settings. Contact
factory.
MANUAL - Push reset
switch or cycle power.
E 32
Mains supply voltage
< 108 VAC.
Boiler shuts off/will
not run.
Check supply voltage.
AUTOMATIC
E 40
Low water flow.
Boiler shuts off/will
not run.
Check water flow, flow switch
(or LWCO) operation.
AUTOMATIC
E 41
Presence of air in the
pump (only with
SensorLogic)
n/a
n/a
n/a
E 42
Pump blocked (only
with SensorLogic)
n/a
n/a
n/a
E 43
Pump wire failure
(only with
SensorLogic)
n/a
n/a
n/a