How to Clear DELLA Fault Codes: A Comprehensive Guide

Clearing DELLA fault codes can be a daunting task, but with the right approach, you can easily resolve the issue and get your system back up and running. This comprehensive guide will walk you through the step-by-step process of clearing DELLA fault codes, covering everything from identifying the error code to implementing the appropriate troubleshooting techniques.

Identifying the Error Code

The first step in clearing DELLA fault codes is to identify the specific error code you are encountering. DELLA systems typically display error codes that provide valuable information about the underlying issue. Some common DELLA error codes include:

  1. F1 Error Code: Indicates a temperature sensor malfunction.
  2. OA Error Code: Signifies a general system error.
  3. E1 Error Code: Denotes a compressor or refrigerant issue.
  4. E5 Error Code: Suggests a problem with the indoor unit’s fan motor.

By understanding the meaning of the error code, you can tailor your troubleshooting efforts to address the specific problem.

Cleaning the Temperature Sensor (F1 Error Code)

how to clear DELLA fault codes

If you are encountering the F1 error code, which indicates a temperature sensor malfunction, you can try cleaning the temperature sensor located inside the head unit. This sensor is responsible for measuring the air temperature that is being heated or cooled.

To clean the temperature sensor:

  1. Locate the head unit and remove the cover to access the internal components.
  2. Identify the temperature sensor, which is typically a small, cylindrical component.
  3. Use a clean, dry cloth or a soft-bristled brush to gently wipe away any dust or debris that has accumulated on the sensor.
  4. Ensure that the sensor is free from any obstructions or contaminants that could interfere with its proper functioning.
  5. Reassemble the head unit and test the system to see if the F1 error code has been cleared.

It is recommended to clean the temperature sensor and the inside cover of the unit at least every six months to prevent the F1 error code from reappearing.

Resetting the Unit (OA Error Code)

For other error codes, such as the OA error code, resetting the unit may be necessary. To reset the unit:

  1. Locate the breaker for the HEAT PUMP / AC in your main electric panel.
  2. Turn the breaker off and wait for a few minutes.
  3. Turn the breaker back on to reset the unit.

This process should clear any error codes that were present and allow the system to restart without the error.

Clearing Fault Codes Using the Diagnostic Connector

If you are unable to clear the error code using the previous methods, you may need to use the diagnostic connector to read and clear the fault codes.

To clear fault codes using the diagnostic connector:

  1. Locate the diagnostic connector on your DELLA unit. This is typically a set of terminals or a port that allows you to interface with the system’s diagnostic functions.
  2. Using a jumper wire, bridge the terminals 1 and 8 on the diagnostic connector. This will put the system into diagnostic mode and allow you to read the fault codes.
  3. Note down the fault codes displayed on the unit.
  4. Leave the ignition on and reconnect the jumper between terminals 1 and 8 for two seconds or more.
  5. Remove the jumper, and the system should display a diagnostic validation code, indicating that the diagnostics are working properly and the fault codes have been cleared.

It’s important to note that clearing the fault codes does not address the underlying issue that caused the error code to appear in the first place. After clearing the codes, it is recommended to troubleshoot the system and address the root cause to prevent the error code from reappearing.

Advanced Troubleshooting Techniques

If the above methods do not resolve the issue, you may need to employ more advanced troubleshooting techniques. This may include:

  1. Checking Electrical Connections: Inspect all electrical connections, including wiring, terminals, and contacts, for any signs of damage, corrosion, or loose connections. Tighten or replace any faulty components as needed.
  2. Verifying Sensor Functionality: Use a multimeter to test the temperature sensor and other relevant sensors to ensure they are functioning correctly. Replace any faulty sensors.
  3. Analyzing Refrigerant Levels: If the issue is related to the compressor or refrigerant, you may need to check the refrigerant levels and recharge the system if necessary.
  4. Replacing Faulty Components: In some cases, the error code may be caused by a malfunctioning component, such as the compressor, fan motor, or control board. Replacing the faulty component may be necessary to resolve the issue.

Remember to always follow the manufacturer’s instructions and safety guidelines when working on DELLA systems. If you are not comfortable performing advanced troubleshooting or repairs, it is recommended to consult a professional HVAC technician.


Clearing DELLA fault codes can be a straightforward process, but it requires a systematic approach and a good understanding of the system’s components and troubleshooting techniques. By following the steps outlined in this comprehensive guide, you can effectively clear DELLA fault codes and get your system back to optimal performance.

Remember, clearing the fault codes is just the first step. It is essential to address the underlying issue that caused the error code to appear in the first place to prevent the problem from recurring. With the right knowledge and tools, you can become a DIY expert in clearing DELLA fault codes and maintaining your HVAC system.


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