Vokera A07 Fault

Vokera A07 Fault

The Vokèra A07 error code signifies a Domestic Hot Water (DHW) Thermistor Fault within the boiler. This thermistor is responsible for monitoring the temperature of the hot water supplied by the boiler to taps and showers. A fault in the DHW thermistor can lead to issues with water temperature regulation, potentially causing the water to be too hot or too cold.

Causes of Vokèra A07 Error Code

  1. Faulty DHW Thermistor: If the thermistor itself is malfunctioning or damaged, it may provide incorrect temperature readings to the boiler’s control unit.
  2. Wiring Issues: Problems with the wiring connections between the DHW thermistor and the boiler’s control board can disrupt the accurate transmission of temperature data.
  3. Limescale Build-up: Accumulation of limescale around the thermistor can insulate it, affecting its ability to accurately measure water temperature.
  4. Poor Sensor Placement: Incorrect placement of the DHW thermistor within the hot water system can lead to inaccurate temperature readings.

Troubleshooting and Resolving the Vokèra A07 Error Code

  1. Inspect and Clean the DHW Thermistor: Check the DHW thermistor for any visible signs of damage or buildup. Carefully cleaning the sensor might help improve its accuracy.
  2. Check Wiring and Connections: Ensure that all connections between the DHW thermistor and the boiler’s control unit are secure and in good condition. Repair or replace any damaged wiring.
  3. Descale the Hot Water System: If limescale is suspected to be affecting the thermistor’s performance, consider descaling the hot water system. This task is often best left to a professional.
  4. Verify Thermistor Placement: Make sure the DHW thermistor is correctly positioned as per the manufacturer’s instructions. Adjustments or repositioning may require professional assistance.
  5. Reset the Boiler: After addressing any issues with the DHW thermistor or the hot water system, try resetting the boiler to see if the error code clears and normal operation resumes.
  6. Professional Diagnosis and Replacement: If the problem persists or you’re unsure how to proceed, it’s advisable to consult a Gas Safe registered engineer. A professional can accurately diagnose the issue and replace the DHW thermistor if necessary.
  7. Regular Maintenance: To prevent future occurrences of error code A07 and other issues, ensure your boiler and hot water system receive regular maintenance from a qualified technician. This can help identify and resolve potential problems early on.


The Vokèra A07 error code highlights a problem with the Domestic Hot Water thermistor, necessitating prompt attention to maintain proper hot water temperature regulation. While some initial checks and cleaning can be done by homeowners, more complex issues related to thermistor functionality or system descaling typically necessitate professional intervention. Regular servicing can help maintain optimal system performance and prevent similar faults.