Emergency function is activated for heating circuit 2 due to lead break, flow temperature sensor, or incorrect setting during commissioning. 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. Check setting in the commissioning assistant and correct if required. Checking setting of ADIO rotary switch.”
- Model
- Viessmann Vitodens 111-W
- Display shows
- 544
- Type
- Fault code
- Source
- Manual p. 82
What 544 means
Emergency function operating mode is activated for heating circuit 2: Mixer closes. Heating circuit pump is operational. p. 82
Common causes
- Lead break, flow temperature sensor, heating circuit 2 with mixer Incorrect setting during commissioning 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. Check setting in the commissioning assistant and correct if required. Checking setting of ADIO rotary switch. p. 82
If 544 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 544; 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.