F93 - Poor combustion quality detected

What does F93 mean?

The Vaillant Ecotec Plus Boilers' combustion regulation system has identified that the quality of combustion is not optimal. This can affect the boiler's efficiency, emissions, and overall safety.

• Incorrect gas restrictor has been installed for the gas family.
• Recirculation issues within the combustion system.
• Mass flow sensor or Venturi is defective, possibly due to being wet or blocked.

Click steps to track your progress.

1. 1

   Ensure the correct gas restrictor is installed for your specific gas family.

2. 2

   Check for any signs of recirculation within the boiler's combustion system.

3. 3

   Inspect the mass flow sensor and Venturi for any blockages, moisture, or damage; avoid using lubricants on the O-ring.

4. 4

   Contact a qualified heating engineer to diagnose and rectify combustion quality issues, as specialized tools are often required.