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Vaillant · Heat pumps · Vaillant aroTHERM plus with uniTOWER plus

F.9998Connection fault: Heat pump

Name in the manufacturer's documentation (service manual): Connection fault: Heat pump[1]

In plain words (editorial)

No connection to the heat pump (outdoor unit): the manual names an eBUS cable that is not connected or connected incorrectly, or the outdoor unit having no supply voltage.

When to call a service technician: Check that the outdoor unit's power supply is switched on; otherwise contact a heating engineer.

✎ editorial – written from the cited sources, not a manufacturer statement. Status: draft.

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. [1] Vaillant uniTOWER plus VIH QW 190/6 E – Operating, installation and maintenance instructions (0020291525_05) (0020291525_05) , p. 64 official manufacturer document quote verified F.9998
  2. [2] Vaillant uniTOWER plus VIH QW 190/6 E – Operating, installation and maintenance instructions (0020291525_05) (0020291525_05) , p. 64 official manufacturer document quote verified eBUS cable not connected or con- nected incorrectly
  3. [3] Vaillant uniTOWER plus VIH QW 190/6 E – Operating, installation and maintenance instructions (0020291525_05) (0020291525_05) , p. 64 official manufacturer document quote verified Outdoor unit without supply voltage
  4. [4] Vaillant uniTOWER plus VIH QW 190/6 E – Operating, installation and maintenance instructions (0020291525_05) (0020291525_05) , p. 64 official manufacturer document quote verified Check the connection pipes between the power supply PCB and control PCB on the indoor and outdoor unit