Ariston 504 Fault

Ariston 504 Fault

The Ariston error code 504 typically indicates a flame lift or flame detection fault during operation. This means the boiler’s control system has detected an unexpected extinguishing of the burner flame under normal operating conditions. Such a fault can pose safety concerns and affect the boiler’s efficiency and heating performance.

Causes of Error Code 504

  1. Intermittent Gas Supply: Fluctuations in the gas supply can cause the flame to extinguish unexpectedly.
  2. Faulty Gas Valve: A malfunctioning gas valve may not provide a consistent gas flow to maintain a stable flame.
  3. Blocked Burner: Debris or corrosion within the burner can affect the gas flow and flame stability.
  4. Flue or Air Supply Issues: Obstructions in the flue or issues with the air supply can disrupt the combustion process, leading to flame instability.
  5. Faulty Flame Sensor: The flame sensor detects the presence of a flame; if it’s faulty, it may incorrectly signal that the flame has lifted.
  6. Control Board Problems: The boiler’s control board orchestrates the operation. Faults here can lead to improper management of the combustion process.

Troubleshooting and Resolving Error Code 504

  1. Check Gas Supply: Ensure the gas supply is consistent and not subject to interruptions. You might need to consult with your gas supplier if you suspect supply issues.
  2. Inspect and Clean the Burner: Check the burner for blockages or signs of corrosion and clean it as necessary. This task should ideally be performed by a professional.
  3. Evaluate the Flue and Air Intakes: Make sure the flue and air intakes are clear of obstructions to ensure proper ventilation and combustion.
  4. Test the Gas Valve: The operation of the gas valve should be checked by a professional, as it requires specific tools and expertise to diagnose and repair.
  5. Inspect the Flame Sensor: Clean or adjust the flame sensor. If it appears to be faulty, it should be replaced by a qualified technician.
  6. Consult a Professional: Given the potential complexity and safety concerns associated with error code 504, it’s advisable to contact a Gas Safe registered engineer for a comprehensive diagnosis and repair.
  7. Regular Maintenance: To prevent future occurrences of error code 504 and ensure the boiler operates efficiently, schedule regular maintenance checks with a qualified professional. This can help identify and rectify potential issues before they lead to faults.


The Ariston error code 504 indicates a flame detection or stability issue that requires immediate attention. While homeowners can perform basic checks, resolving the underlying cause of a flame lift fault typically necessitates professional intervention. Regular servicing and maintenance are essential for preventing such issues, ensuring the safe and efficient operation of your heating system.