Brand: Allied Air Enterprises
Category: Heat Pump
Manual Type:
Language:
Manual for 4HP16LT Series - Troubleshooting and error codes + PDF Download
Uploaded: April 1, 2025, 12:48 a.m.
Warranty Summary
Warranty information is not provided in this installation manual.
The 4HP16LT Series heat pump operates on demand from the room thermostat. When the thermostat calls for heating or cooling, the outdoor unit and indoor blower will cycle. The indoor blower can also operate continuously if set to the ON position.
Key Operational Features:
- Filter Drier: Equipped with a bi-flow filter to maintain system cleanliness and dryness.
- Crankcase Heater: May be included to prevent compressor damage from slugging during start-up in cold conditions.
- Emergency Heat: Some thermostats offer an emergency heat function to isolate the outdoor unit and utilize auxiliary heat in emergencies.
- Demand Defrost: Monitors temperature differentials to initiate defrost cycles only when needed, optimizing efficiency and reducing unnecessary defrosting.
Troubleshooting and error codes
{/* Use for empty cells if needed */}
| DS2 Green | DS1 Red | Condition / Code | Possible Cause(s) | Solution |
|---|---|---|---|---|
| Off | Off | Power problem | No power (24V) to board terminals R & C or board failure. | 1 Check control transformer power (24V).2 If power is available to board and LED(s) do not light, replace board. |
| Simultaneous SLOW flash |
Simultaneous SLOW flash |
Normal operation | Unit operating normally or in standby mode. | None required. |
| Alternating SLOW flash |
Alternating SLOW flash |
5-minute anti-short cycle delay | Initial power up, safety trip, end of room thermostat demand. | None required (Jumper TEST pins to override) |
| Simultaneous FAST flash |
Simultaneous FAST flash |
Ambient sensor problem | Sensor being detected open or shorted or out of temperature range. Board will revert to time/temperature defrost operation. (System will still heat or cool) | |
| Alternating FAST flash |
Alternating FAST flash |
Coil sensor problem | Sensor being detected open or shorted or out of temperature range. Board will not perform demand or time/temperature defrost operation. (System will still heat or cool) | |
| On | On | Circuit board failure | Indicates that board has internal component failure. Cycle 24V power to board. If code does not clear, replace board. |
Troubleshooting and error codes
{/* Use for empty cells if needed */}
| DS2 Green | DS1 Red | Condition / Code | Possible Cause(s) | Solution |
|---|---|---|---|---|
| Off | Off | Power problem | No power (24V) to board terminals R & C or board failure. | 1 Check control transformer power (24V).2 If power is available to board and LED(s) do not light, replace board. |
| Simultaneous SLOW flash |
Simultaneous SLOW flash |
Normal operation | Unit operating normally or in standby mode. | None required. |
| Alternating SLOW flash |
Alternating SLOW flash |
5-minute anti-short cycle delay | Initial power up, safety trip, end of room thermostat demand. | None required (Jumper TEST pins to override) |
| Simultaneous FAST flash |
Simultaneous FAST flash |
Ambient sensor problem | Sensor being detected open or shorted or out of temperature range. Board will revert to time/temperature defrost operation. (System will still heat or cool) | |
| Alternating FAST flash |
Alternating FAST flash |
Coil sensor problem | Sensor being detected open or shorted or out of temperature range. Board will not perform demand or time/temperature defrost operation. (System will still heat or cool) | |
| On | On | Circuit board failure | Indicates that board has internal component failure. Cycle 24V power to board. If code does not clear, replace board. |