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Daikin · Heat pumps · Daikin Altherma 3 R F (split heat pump, R32)

A5-00OU: High pressure peak cut / freeze protection problem

Name in the manufacturer's documentation (service manual): OU: High pressure peak cut / freeze protection problem[1]

In plain words (editorial)

High pressure peak cut or freeze protection problem of the outdoor unit. The manual names too low water pressure, too low water flow or a closed stop valve in the water circuit.

When to call a service technician: Check the water pressure and that the valves are open; if the code repeats, contact your installer.

✎ 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] Daikin Altherma 3 R F – ERGA04~08E + EHVH/X04+08S18+23E – Installer reference guide (4P629086-1D (2024.04)) , p. 254 official manufacturer document quote verified A5-00 OU: High pressure peak cut / freeze protection problem
  2. [2] Daikin – Service manual Daikin Altherma 3 R F + W, ESIE20-13C – 2022.09 (PDF copy on installer site cncpompyciepla.pl) (ESIE20-13C) , p. 28 manufacturer document – copy from a distributor quote verified water pressure is too low.
  3. [3] Daikin – Service manual Daikin Altherma 3 R F + W, ESIE20-13C – 2022.09 (PDF copy on installer site cncpompyciepla.pl) (ESIE20-13C) , p. 28 manufacturer document – copy from a distributor quote verified water flow is too low.
  4. [4] Daikin – Service manual Daikin Altherma 3 R F + W, ESIE20-13C – 2022.09 (PDF copy on installer site cncpompyciepla.pl) (ESIE20-13C) , p. 28 manufacturer document – copy from a distributor quote verified closed stop valve in the water circuit.
  5. [5] Daikin – Service manual Daikin Altherma 3 R F + W, ESIE20-13C – 2022.09 (PDF copy on installer site cncpompyciepla.pl) (ESIE20-13C) , p. 28 manufacturer document – copy from a distributor quote verified check the water pressure.
  6. [6] Daikin – Service manual Daikin Altherma 3 R F + W, ESIE20-13C – 2022.09 (PDF copy on installer site cncpompyciepla.pl) (ESIE20-13C) , p. 28 manufacturer document – copy from a distributor quote verified check the water flow.
  7. [7] Daikin – Service manual Daikin Altherma 3 R F + W, ESIE20-13C – 2022.09 (PDF copy on installer site cncpompyciepla.pl) (ESIE20-13C) , p. 28 manufacturer document – copy from a distributor quote verified check that all stop valves of the water circuit are open.