Viessmann Vitodens 100-W fault 12

Short circuit, collector temperature sensor

Gas boiler

What it means

No solar DHW heating. Short circuit detected on the collector temperature sensor.

Likely causes

  1. Server temporarily unavailable
  2. Internet connectivity issue beyond the local router
  3. Short circuit, collector temperature sensor

Where to start

  1. Re-establish the connection at a later time
  2. Check collector temperature sensor
  3. Measure voltage at sensor input on electronics module (ADIO)

The full answer, free

  • 1 more check 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 68), 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