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Viessmann · Heat pumps · Viessmann Vitocal 250-A (One Base, monobloc)

F.998Flow rate signal faulty

Name in the manufacturer's documentation (service manual): Flow rate signal faulty[1]

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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] Viessmann – Service instructions: System configuration and diagnosis for heat pumps with Viessmann One Base (6194799 GB, 3/2022) (6194799 GB (3/2022)) , p. 66 manufacturer document – copy from a distributor quote verified F.998
  2. [2] Viessmann – Service instructions: System configuration and diagnosis for heat pumps with Viessmann One Base (6194799 GB, 3/2022) (6194799 GB (3/2022)) , p. 66 manufacturer document – copy from a distributor quote verified Check flow sensor
  3. [3] Viessmann – Service instructions: System configuration and diagnosis for heat pumps with Viessmann One Base (6194799 GB, 3/2022) (6194799 GB (3/2022)) , p. 66 manufacturer document – copy from a distributor quote verified Replace if re- quired
  4. [4] Viessmann – Service instructions: System configuration and diagnosis for heat pumps with Viessmann One Base (6194799 GB, 3/2022) (6194799 GB (3/2022)) , p. 66 manufacturer document – copy from a distributor quote verified Check CAN bus connections: – CAN bus cable, indoor/outdoor unit – Check connection X19 on EHCU electronics module. – Check connections X4 on HPMU electronics module. – Check connection X5 on EHCU electronics module
  5. [5] Viessmann – Service instructions: System configuration and diagnosis for heat pumps with Viessmann One Base (6194799 GB, 3/2022) (6194799 GB (3/2022)) , p. 66 manufacturer document – copy from a distributor quote verified Isolate the system from the
  6. [6] Viessmann – Service instructions: System configuration and diagnosis for heat pumps with Viessmann One Base (6194799 GB, 3/2022) (6194799 GB (3/2022)) , p. 66 manufacturer document – copy from a distributor quote verified Restart the system
  7. [7] Viessmann – Service instructions: System configuration and diagnosis for heat pumps with Viessmann One Base (6194799 GB, 3/2022) (6194799 GB (3/2022)) , p. 66 manufacturer document – copy from a distributor quote verified If the fault persists, replace the CAN bus cable
  8. [8] Viessmann – Service instructions: System configuration and diagnosis for heat pumps with Viessmann One Base (6194799 GB, 3/2022) (6194799 GB (3/2022)) , p. 66 manufacturer document – copy from a distributor quote verified Replace EH- CU electronics module if re- quired
  9. [9] Viessmann – Service instructions: System configuration and diagnosis for heat pumps with Viessmann One Base (6194799 GB, 3/2022) (6194799 GB (3/2022)) , p. 66 manufacturer document – copy from a distributor quote verified Replace HPMU electron- ics module if required
  10. [10] Viessmann – Service instructions: System configuration and diagnosis for heat pumps with Viessmann One Base (6194799 GB, 3/2022) (6194799 GB (3/2022)) , p. 66 manufacturer document – copy from a distributor quote verified If the fault occurs repeatedly,
  11. [11] Viessmann – Service instructions: System configuration and diagnosis for heat pumps with Viessmann One Base (6194799 GB, 3/2022) (6194799 GB (3/2022)) , p. 66 manufacturer document – copy from a distributor quote verified The refrigerant circuit will not start