Viessmann 200 and 222 fault fault 33

Power supply voltage is below minimal operating level; internal fuse failure

Gas boiler

What it means

Burner in hold/wait state, boiler not displaying fault; refer to coding address 38:XX. Power supply voltage below minimal operating level; internal fuse failure

Likely causes

  1. Power supply voltage below minimal operating level
  2. Internal fuse failure

Where to start

  1. Check power
  2. Replace control if needed

The full answer, free

  • How to put it right, step by step
  • The manual page for this fault (page 3), 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