Troubleshooting; Control Diagnostic Modes - Friedrich VERT-I-PAK VHA09K25RTQ Service Manual

Control Diagnostic Modes

Control Diagnostic Modes
Diagnostic Description
Control Fault (No Power)
Normal Operation
Anti-Short Cycle Delay
Coil Sensor Failure
Ambient Sensor Failure
Low Pressure Switch Open
Low Pressure Switch
Lockout
High Pressure Switch Open
High Pressure Switch
Lockout
31

TROUBLESHOOTING

LED 1 LED 2
Off Off Confirm incoming voltage, if present replace the board.
Flash Flash Normal operation.
Alternating Wait for shot cycle delay to expire. Approximately 3-minutes.
Flash
On On 1. An open or shorted sensor is detected.
2 .Confirm connection points.
3. Ohm out sensor to confirm if open (OL) or shorted (0.0 Ohms). If ok replace the board.
Refer to Appendix 1 (Thermistor resistor values).
Off On 1. An open or shorted sensor is detected.
2. Confirm connection points.
3 .Ohm out sensor to confirm if open (OL or shorted (0.0 Ohms). If ok replace the board.
Refer to Appendix 1 (Thermistor resistor values).
On Flash 1. Possible faulty pressure switch.
2. Confirm connection points.
3 .Suction line pressure is too low. Confirm system pressures and operation, address as
needed.
4 .In cooling possible indoor blower not running.
Off Flash 1. Possible faulty pressure switch.
2. Confirm connection points.
3 .Suction line pressure is too low. Confirm system pressures and operation, address as
needed.
4 .In cooling possible indoor blower not running.
Flash On 1. Possible faulty pressure switch.
2 .Confirm connection points.
3 .Discharge pressure too high. Confirm system pressures and operation, address as
needed.
4 .In cooling possible outdoor condensing fan motor not running.
Flash Off 1. Possible faulty pressure switch.
2 .Confirm connection points.
3 .Discharge pressure too high. Confirm system pressures and operation, address as
needed.
4 .In cooling possible outdoor condensing fan motor not running.
Solution