Emergency function is activated for heating circuit 2 due to short circuit in the flow temperature sensor with mixer. The manual's first action is: “Check flow temperature sensor, mixer 2. Measure voltage at sensor input on electronics module. Set value: 3.3 V– with sensor disconnected”
- Model
- Viessmann Vitodens 111-W
- Display shows
- 545
- Type
- Fault code
- Source
- Manual p. 82
What 545 means
Emergency function operating mode is activated for heating circuit 2: Mixer closes. Heating circuit pump is operational. p. 82
Common causes
- Short circuit, flow temperature sensor for heating circuit 2 with mixer p. 82
What to do
- Check flow temperature sensor, mixer 2. Measure voltage at sensor input on electronics module. Set value: 3.3 V– with sensor disconnected p. 82
If 545 is still not resolved
The manual gives no further instruction for this code. Open the code table in the PDF or contact Viessmann service.
This page summarises what the manufacturer’s manual says about 545; each statement links to the page it comes from, and quoted lines are copied word for word. It is not a substitute for the manual or for a qualified installer. ManualLib is not affiliated with Viessmann. Found a mistake? Report an error.