Brand: Allied Air Enterprises
Category: Heat Pump
Document Type:
Language: EN
Manual for 4SCU20LX 4SHP20LX - Troubleshooting and error codes + PDF Download
Uploaded: March 30, 2025, 4:26 p.m.
Manual Publish Date: 2015-08-01
Warranty Summary
No warranty information provided in this manual.
Power-Up/Outdoor Reset Sequence:
- Initiates a 3-minute anti-short cycle delay.
- Checks temperature and pressure sensors.
- If no errors, energizes CNTCTR terminals to engage contactor coil (approx. 60 seconds).
- Contactor pulls in, applying main power to the compressor inverter.
Operational Response:
- Thermostat sends cooling percentage demand.
- Outdoor control demands compressor start and capacity, and fan motor operation.
- Indoor unit receives signal to start supply fan at demanded CFM.
Troubleshooting and error codes
| Alert Codes | Inverter Code | Inverter LED Flash Code | Priority | Alarm Description | Possible Causes and Clearing Alarm |
|---|---|---|---|---|---|
| E 105 | N/A | N/A | Moderate | Outdoor control lost communication with thermostat or indoor unit. | Check wiring, noise sources. Resets after communication restored. |
| E 120 | N/A | N/A | Moderate | Delay in outdoor unit responding to system. | Check wiring. Clears automatically. |
| E 124 | N/A | N/A | Critical | Wi-Fi® thermostat lost communication with outdoor unit. | Check wiring, power cycle. Clears after communication re-established. |
| E 125 | N/A | N/A | Critical | Hardware problem with outdoor control. | Replace outdoor control. Clears after 300 seconds if recovered. |
| E 131 | N/A | N/A | Critical | Outdoor unit control parameters corrupted. | Reconfigure system. Replace control if needed. |
| E 132 | N/A | N/A | Critical | Internal software error. | Replace outdoor control. |
| E 180 | N/A | N/A | Critical | Outdoor ambient temperature sensor malfunctioned. | Check/replace sensor. Clears upon configuration or normal values. |