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P/N SCM2-0111
Model
SCM
Air to Water Heat Pump — Installation, Operation & Maintenance Manual
Section 8: troubleshooting
(continued)
Figure 14
Fault codes
FAULT
CODE
MALFUNCTION
REASON
ACTION
E1
Water Inlet Temperature Sensor
Failure
Short Circuit or Sensor Open
Check/Replace Sensor
E2
Water Outlet Temperature Sensor
Failure
Short Circuit or Sensor Open
Check/Replace Sensor
E3
Evaporator Sensor Failure
Short Circuit or Sensor Open
Check/Replace Sensor
AL
Anti-Freeze Cycle Error / Cooling
Water Temperature has Fallen
Below Antifreeze Protection
Setpoint
Check Flow Rate
Check For Blockage in Piping
FL
Flow Switch Error
Inadequate Water Flow Rate
Verify or Increase Glycol Concentration
and Contact Mestek Technical Support for
Instructions to Lower Alarm Setpoint
HP1/HP2
High Pressure Alarm
System1/System2
Discharge Pressure Exceeds
Maximum Allowable
Cooling Mode:
Check for Dirty Coil
Check for Restricted Air Flow
Check for Excessive Ambient Temperature
Heating Mode:
Check for Sufficient Water Flow Rate
LP1/LP2
Low Pressure Alarm
System1/System2
Suction Pressure Below
Minimum Allowable
Cooling Mode:
Check for Sufficient Water Flow Rate
Heating Mode:
Check for Dirty Coil
Check for Restricted Air Flow
Check for Low Ambient Temperature