MC2: 10/03/12 Page
69
of
90
AERCO International, Inc.
•
100 Oritani Dr.
•
Blauvelt, NY 10913
•
Ph: 800-526-0288
GF-115-H
OMM-0083_0B
Modulex MLX Series Gas Fired Boiler System
Operation and Maintenance Manual
Chap 10:
Troubleshooting
FAULT
INDICATION
PROBABLE
CAUSES
CORRECTIVE ACTION
E13:
Auxiliary sensor
failure (DHW)
1. Open sensor circuit
2. Temperature out of
range
3. Loose or broken
wiring.
4. Defective Sensor.
5. Incorrect Sensor.
1. Check circuit continuity and replace if defective.
2. ??
3. Inspect Outdoor Temperature sensor for loose or
broken wiring.
4. Check resistance of sensor to determine if it is within
specification.
5. Ensure that the correct sensor is installed.
E14:
Return
temperature
sensor failure
(SRR)
Surface mount
sensor
1. Open sensor circuit
2. Temperature out of
range
3. Loose or broken
wiring.
4. Defective Sensor.
5. Incorrect Sensor.
1. Check circuit continuity and replace if defective.
2. ??
3. Inspect Outdoor Temperature sensor for loose or broken
wiring.
4. Check resistance of sensor to determine if it is within
specification.
5. Ensure that the correct sensor is installed.
E15:
Difference
between the
global flow
(supply/outlet)
temperature
sensor and the
return/inlet
temperature
sensor exceeds
72°F
This type of error code
typically indicates that
there is a water
circulation problem.
Examples when such a
situation might occur
includes situations
where the filter is dirty
or the pump is too small
(or damaged) with
respect to the power of
the boiler.
This error code is
presented when the
Δ-
temperature
= flow
temperature –
RetSensor
temperature is > 40°C
(104°F). It is cleared
when Δ-
temperature
<
30 °C (86 °F)
.
Check all possible causes of failed water circulation.
Included here would be a dirty filter, a malfunctioning water
pump, etc.
E16:
Low temperature
condition may
cause risk of
freezing
1. Faulty controller
circuit not starting
boiler when
ambient temp is
less than 37.4ºF
(3ºC)
1. Replace controller circuit
2. Check return sensor and replace if damaged.
Table 10-1: Boiler Troubleshooting – PCB Terminal (Continued)
