Viessmann 200 and 222 fault fault EA

Ionization current outside permissible range during calibration (deviation too great)

Gas boiler

What it means

Burner in fault mode due to detailed code 193: ionization current outside permissible range during calibration, deviation from previous level too great

Likely causes

  1. Flue gas recirculation
  2. Dusty combustion air in open flue mode
  3. Boiler coding card issue after repeated resets

Where to start

  1. Check flue system; remedy flue gas recirculation if required
  2. In open flue mode, prevent very dusty conditions for the combustion air
  3. Following several unsuccessful reset attempts, replace boiler coding card and press reset button R

The full answer, free

  • How to put it right, step by step
  • The manual page for this fault (page 1), 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