Viessmann Vitodens 100-W fault 369

Flame lost immediately after flame formation (during safety time)

Gas boiler

What it means

Burner in a fault state because the flame is lost immediately after flame formation, during the safety time period.

Likely causes

  1. Air in gas line
  2. Gas supply issues (gas pressure and gas flow switch)

Where to start

  1. Verify ionisation current builds; if not, fault 369/380 - check ionisation electrode distance, purge gas line.
  2. Check gas supply (gas pressure and gas flow switch).

The full answer, free

  • How to put it right, step by step
  • The manual page for this fault (page 77), 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 Vitodens 100-W. Check the model on the data plate before you order parts.

Other Viessmann Vitodens 100-W fault codes