Potterton E119 Fault

Potterton E119 Fault

The Potterton E119 error code signifies a situation where the boiler is experiencing low water pressure. This condition occurs when the pressure in the central heating system falls below the minimum threshold required for the boiler to operate safely and efficiently. Low water pressure can affect the performance of your heating system, leading to inadequate heating or, in some cases, preventing the boiler from working entirely.

Causes of Potterton E119 Error Code

  1. Leaks in the Heating System: Small leaks within the radiators, pipework, or boiler components can cause a gradual loss of water, leading to a drop in system pressure.
  2. Recently Bled Radiators: Bleeding radiators to remove air can also reduce the system’s water pressure if the system is not subsequently repressurized.
  3. Faulty Pressure Relief Valve: If the pressure relief valve is leaking water, it can lead to a decrease in system pressure.

Troubleshooting and Resolving the Potterton E119 Error Code

  1. Check for Visible Leaks: Inspect the heating system, including radiators, pipework, and the boiler itself, for any signs of leaks. Any leaks found should be repaired to prevent further loss of pressure.
  2. Repressurize the System: If the system pressure is low, use the boiler’s filling loop to repressurize the system to the recommended level, typically around 1-1.5 bar. The specific procedure for repressurizing your boiler should be outlined in the boiler’s user manual.
  3. Bleed Radiators: If you have recently bled your radiators, ensure that you repressurize the system afterward to maintain the correct pressure level.
  4. Check the Pressure Relief Valve: Inspect the pressure relief valve for signs of leakage or malfunction. A constantly dripping pressure relief valve indicates that it may need to be replaced.
  5. Reset the Boiler: After addressing the low pressure issue and repressurizing the system, reset the boiler to clear the E119 error code and resume normal operation.
  6. Seek Professional Assistance: If you are unable to identify the cause of the low pressure or if the problem persists after taking corrective action, it is advisable to contact a Gas Safe registered engineer for a professional diagnosis and repair.


The Potterton E119 error code is a common issue that often can be resolved by identifying and repairing leaks, repressurizing the system, or replacing faulty components like the pressure relief valve. Regular checks of the system pressure and timely maintenance can help prevent this issue, ensuring that your boiler operates efficiently and reliably.