Ariston 302 Fault

Ariston 302 Fault

The fault of the flow temperature sensor is indicated by a 302 Ariston error code. The sensor checks the temperature of water going out from the boiler, and if it does not do this, it means that either it is broken or there are some other problems with the boiler so that it cannot measure accurately.
Causes of Error Code 302

Defective Flow Temperature Sensor: This situation might arise as a consequence of malfunctions or physical damage to the sensor leading to mistakes in temperature data transmission to the control unit of a boiler.

Poor Connections or Wiring Issues: Loose wiring connections at flow temperature sensor’s end can cause disruptions during transmission of temperature readings to central control board within a boiler.

Sludge or Scale Build-up: Water temperature in your heating system could be affected in case there is sludge/scale building up inside your boiler causing wrong readings on a thermal resistor.

System Air Locks: Temperature reading accuracy can also be tampered with when air bubbles are trapped inside an appliance loop making others feel sluggish about its operations.

Boiler Overheating: In cases like pump failure or limited flow, overheating may lead to abnormal values on flow temperature sensors as they respond to such operational conditions.

Troubleshooting and Resolving Error Code 302

Inspect and Clean the Sensor: Inspect for any damage or corrosion signs on thermisor. It should be cleaned without causing any harm for accurate measurements of its body temperatures.

Check Wiring and Connections : Ensure all electrical connections between the sensor and the boiler’s control unit are secure and undamaged. Replace any faulty wiring connections you find.

Bleed the System: By bleeding radiators and heating system you will help remove air locks which may hinder proper water circulation hence poor measurement quality for liquid temperatures.

Flushing System : You should consult an expert technician who can flush this heating system on behalf of you just in order to get rid off these sludge/ scales impairing the temperature readings.

Reset the Boiler: After resolving any potential issues, attempt to reset the boiler and check if the error clears and normal operation resumes.

Professional Diagnosis and Replacement: If the problem persists or you’re unsure how to proceed, consult a professional. A Gas Safe registered engineer can accurately diagnose the issue, potentially replacing the flow temperature sensor if it’s found to be faulty.

Regular Maintenance: Prevent future occurrences of error code 302 and other issues by ensuring your boiler and heating system receive regular professional maintenance. This can help identify and address potential problems before they lead to system faults.


The prompt attention is needed in an Ariston error code 302 that points out a problem with the flow temperature sensors for efficient and safe running of boilers. Although some initial assessments are possible for homeowners, rectification of sensor-related malfunctions often needs assistance from people who possess specialized knowledge. Keeping up with routine servicing practices in good time will ensure your systems remain operational without any hitches like this one.