Vaillant · Heat pumps · Vaillant aroTHERM plus with uniTOWER plus
F.546Sensor fault: High pressure
Name in the manufacturer's documentation (service manual): Sensor fault: High pressure
[1]
In plain words (editorial)
Fault of the high-pressure sensor in the refrigerant circuit. The manual names the cause: the sensor is not connected or its input has short-circuited. The fix (checking or replacing the sensor or its wiring harness) is a job for a competent heating engineer.
When to call a service technician: Contact a competent heating engineer (installer or Vaillant customer service).
✎ editorial – written from the cited sources, not a manufacturer statement. Status: draft.
For technicians
Possible causes (source text)
- The sensor is not connected or the sensor input has short-circuited[2]
Steps given by the manufacturer (source text)
⚠ Work on refrigerant circuits, mains electricity and PV DC wiring is for qualified technicians only.
The Polish page has more detail (plain-language explanation, safe checks, guides): Read in Polish →
Sources
Every statement has a footnote to the document and PDF page. “Quote verified” means the quote was found automatically in the text of that page.
- [1] Vaillant uniTOWER plus VIH QW 190/6 E – Operating, installation and maintenance instructions (0020291525_05) (0020291525_05) , p. 60 official manufacturer document quote verified
F.546 Sensor fault: High pressure
- [2] Vaillant uniTOWER plus VIH QW 190/6 E – Operating, installation and maintenance instructions (0020291525_05) (0020291525_05) , p. 60 official manufacturer document quote verified
The sensor is not connected or the sensor input has short-circuited
- [3] Vaillant uniTOWER plus VIH QW 190/6 E – Operating, installation and maintenance instructions (0020291525_05) (0020291525_05) , p. 60 official manufacturer document quote verified
Check the sensor (e.g. using an in- stallation aid), and replace if neces- sary
- [4] Vaillant uniTOWER plus VIH QW 190/6 E – Operating, installation and maintenance instructions (0020291525_05) (0020291525_05) , p. 60 official manufacturer document quote verified
Replace the wiring harness