Ariston 501 Fault

Ariston 501 Fault

The Ariston error code 501 indicates a problem with flame detection. Specifically, this code is shown when the boiler’s control system attempts to ignite the burner, but no flame is detected, or the flame signal is lost shortly after ignition. This fault suggests issues with the ignition process or the components involved in detecting the flame.

Causes of Error Code 501

  1. Gas Supply Issues: Inadequate gas pressure or interruptions in the gas supply can prevent the burner from igniting properly.
  2. Faulty Ignition Electrodes: Worn or incorrectly positioned ignition electrodes may fail to ignite the gas mixture.
  3. Blocked Burner: Dirt, debris, or corrosion on the burner can obstruct the gas flow or the ignition process.
  4. Flame Sensor Fault: The flame sensor, responsible for detecting whether the burner has successfully ignited, could be faulty or dirty, leading to incorrect flame detection.
  5. Control Board Problems: The boiler’s control board manages the ignition process and monitors the flame sensor’s signal. A fault in the control board can result in failure to detect the flame.

Troubleshooting and Resolving Error Code 501

  1. Check Gas Supply: Ensure the gas supply valve is fully open and that other gas appliances in the property are working. If there’s a wider issue with gas supply, contact your gas supplier.
  2. Inspect and Clean Ignition Electrodes: Check the condition of the ignition electrodes. Cleaning or adjusting them might resolve the issue. However, if they are significantly worn or damaged, replacement is necessary.
  3. Clean the Burner: A clean burner ensures proper gas flow and ignition. Removal of any obstructions or buildup can improve burner operation.
  4. Examine the Flame Sensor: Clean the flame sensor to ensure it can accurately detect the flame. If the sensor is faulty, it may need replacement.
  5. Reset the Boiler: After addressing any potential issues, try resetting the boiler to clear the error code and attempt re-ignition.
  6. Consult a Professional: Due to the technical nature of flame detection and ignition system components, it’s advisable to seek assistance from a Gas Safe registered engineer if the problem persists. A professional can accurately diagnose and safely repair or replace faulty components.


The Ariston error code 501 is a critical indication of issues within the ignition or flame detection system, requiring prompt attention to ensure the boiler operates safely and efficiently. While some preliminary checks and cleaning can be performed by the homeowner, diagnosing and fixing the underlying cause of a flame detection fault often necessitates professional intervention. Regular boiler maintenance and timely component replacement can help prevent such issues, ensuring reliable heating performance.