Viessmann 200 and 222 fault fault F1

Maximum flue gas temperature exceeded 230°F (110°C) limit

Gas boiler

What it means

Burner in fault mode due to detailed code 135: maximum flue gas temperature exceeded 230°F (110°C) limit

Likely causes

  1. Low heating system fill level
  2. Air in system
  3. Circulation pump fault
  4. Boiler water temperature sensor fault

Where to start

  1. Check heating system fill level
  2. Bleed air from system
  3. Check circulation pump

The full answer, free

  • 2 more checks in order
  • The readings and component tests from the manual
  • How to put it right, step by step
  • The manual page for this fault (page 2), right under the answer

Safety: Isolate gas and power before you open the case. If you have been into the gas side, do a tightness test, and a combustion and flue check before you hand back. Gas Safe (UK) or RGI (Ireland) work only.

From the Viessmann manual for the 200 and 222 fault. Check the model on the data plate before you order parts.

Other Viessmann 200 and 222 fault fault codes