Potterton E83, E84, E85 Fault

Potterton E83, E84, E85 Fault

The Potterton boiler error codes E83, E84, and E85 are associated with faults related to the Printed Circuit Board (PCB). These codes indicate issues with the boiler’s electronic control system, which can affect the overall operation and functionality of the boiler. The PCB is crucial for managing and coordinating the operation of different components within the boiler, so faults in this area require immediate attention.

Causes of Potterton E83, E84, and E85 Error Codes

  • E83: Communication Error – This code often indicates a problem with the communication between the boiler’s PCB and its components or external controls.
  • E84: Fault in External Control Device – Suggests an issue with an external control device connected to the boiler, such as a thermostat or timer, that isn’t communicating correctly with the PCB.
  • E85: PCB Lockout – Indicates a more serious fault within the PCB itself, possibly due to a component failure, that has caused the boiler to lock out for safety.

Troubleshooting and Resolving Potterton E83, E84, and E85 Error Codes

  1. Reset the Boiler: Sometimes, a simple reset can clear temporary communication glitches or minor PCB errors. Refer to your boiler’s manual for the correct reset procedure.
  2. Check Electrical Connections: Ensure all electrical connections, especially those related to the PCB and external controls, are secure and in good condition. Loose or damaged connections can cause these error codes.
  3. Inspect External Control Devices (E84): For E84 errors, check any connected external control devices for functionality. Ensure they are properly installed and communicating correctly with the boiler.
  4. Professional Assessment and Repair: Given the complexity of PCB-related issues and the potential for further damage, professional diagnosis and repair are essential. A Gas Safe registered engineer can assess whether the PCB needs reprogramming, repairing, or replacing.
  5. Consider PCB Replacement (E85): In cases where the PCB is locked out or significantly damaged (E85), replacement of the PCB might be necessary. This should only be performed by a qualified professional to ensure correct installation and operation.
  6. Regular Maintenance: Prevent future PCB-related issues by ensuring your boiler undergoes regular professional maintenance. This can help identify potential problems early and maintain optimal boiler performance.


Error codes E83, E84, and E85 on a Potterton boiler indicate significant issues with the PCB or its communication with boiler components and external devices. Due to the technical nature of these faults, professional diagnosis and repair are crucial. Regular servicing can help detect early signs of PCB problems, contributing to the longevity and efficiency of your boiler system.