iFLOW HVAC INC.
www.iflowhvac.com
23
Troubleshooting
1) Fault codes and Explanations:
Segment
Code
Description
Cause
Sensor
001
Supply Air Temp. Sensor
Sensor has no continuity.
Sensor is out of measuring range.
Faulty Sensor.
Check sensor reading against
corresponding temperature sensor
chart. If out of range, replace
sensor.
002
Return Air Temp. Sensor
003
Supply Water Temp. Sensor
004
Return Water Temp. Sensor
005
A/C Evap. Temp. Sensor
006
D.H. Evap. Temp. Sensor
007
Outdoor Temp. Sensor
008
Humidity Sensor
Heat
Exchanger
020
H/ex. Freeze protection
Ambient temperature below 36°F Unit will automatically run circulator
until temperature is increased.
021
H/ex Overheating
Water temperature delta t below
3°F
Ensure proper CFM, GPM. Make
sure no restriction of water flow
and airflow. Check sensor. Replace
if necessary. Check filter. Check
pump operation.
A/C
Evaporator
030
A/C Evap. Freeze protection
Evaporator temperature below
37°F
check airflow. Check refrigerant
level. Check proper A/C operation.
031
A/C Evap. Overheating
Air temperature delta t below 5°F Excessive cfm. Ensure proper A/C
operation
D.H.
Evaporator
040
D.H. Evap. Freeze protection
Evaporator temperature below
37°F
041
D.H. Evap. Overheat
Air temperature delta t below 5°F
Water Flow
060
Abnormal Pump Operation
Improper pump size. Improper
piping. Pump failure. Air in
circulator. Check proper voltage
and connection to circulator.
Ensure all causes are absent. If
so, replace circulator.
Safety
070
Incorrect wiring
Incorrect thermostat/control
wiring
Ensure all connections and tight
and secure.
080
Over Cooling
Return air temperature below
60.8°F during cooling mode
Run blower fan until temperature
returns to normal operating
conditions.
081
Over Heating
Return air temperature above
80°F during heating mode
082
Room Temp. High
Return air temperature above
80°F before a call for heating
083
Room Temp. Low
Return air temperature below
60.8°F before a call for cooling
