Viessmann · Heat pumps · Viessmann Vitocal 250-A (One Base, monobloc)
F.798Heating circuit pump, heating/cooling circuit 2 is faulty
Name in the manufacturer's documentation (service manual): Heating circuit pump, heating/cooling circuit 2 is faulty
[1]
In plain words (editorial)
The heating circuit pump of circuit 2 is faulty and off – no room heating in circuit 2 and no hot water heating. The manual says to isolate the system from the power supply and restart it.
When to call a service technician: If the fault persists, contact your heating contractor (the pump may need replacing).
✎ editorial – written from the cited sources, not a manufacturer statement. Status: draft.
For technicians
Steps given by the manufacturer (source text)
What the device does (source text)
- Heating circuit pump, heating/cooling circuit 2 is off. ■No room heating, heating/ cooling circuit 2 ■No DHW heating[5]
⚠ 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] Viessmann – Service instructions: System configuration and diagnosis for heat pumps with Viessmann One Base (6194799 GB, 3/2022) (6194799 GB (3/2022)) , p. 60 manufacturer document – copy from a distributor quote verified
F.798
- [2] Viessmann – Service instructions: System configuration and diagnosis for heat pumps with Viessmann One Base (6194799 GB, 3/2022) (6194799 GB (3/2022)) , p. 60 manufacturer document – copy from a distributor quote verified
Isolate the system from the power supply
- [3] Viessmann – Service instructions: System configuration and diagnosis for heat pumps with Viessmann One Base (6194799 GB, 3/2022) (6194799 GB (3/2022)) , p. 60 manufacturer document – copy from a distributor quote verified
Restart the system
- [4] Viessmann – Service instructions: System configuration and diagnosis for heat pumps with Viessmann One Base (6194799 GB, 3/2022) (6194799 GB (3/2022)) , p. 60 manufacturer document – copy from a distributor quote verified
If the fault persists, replace heating circuit pump, heating/cooling
- [5] Viessmann – Service instructions: System configuration and diagnosis for heat pumps with Viessmann One Base (6194799 GB, 3/2022) (6194799 GB (3/2022)) , p. 60 manufacturer document – copy from a distributor quote verified
Heating circuit pump, heating/cooling circuit 2 is