Mitsubishi Electric · Heat pumps · Mitsubishi Electric Ecodan PUZ-WM outdoor unit (R32)
ULLow pressure
Name in the manufacturer's documentation (service manual): Low pressure
[1]
This page only quotes the original English documentation. A plain-language explanation has not been written yet, so the page is not indexed by search engines.
For technicians
Detection conditions (source text)
- Abnormal if following conditions are detected after compressor starts heating operating for 3 minutes[2]
Possible causes (source text)
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] Mitsubishi Electric – Service Manual: Air to water heat pump units, outdoor unit PUZ-WM50VHA … PUZ-WM112YAA (OCH727 REVISED EDITION-A, 12/2023) (OCH727A (12/2023)) , p. 29 official manufacturer document quote verified
- [2] Mitsubishi Electric – Service Manual: Air to water heat pump units, outdoor unit PUZ-WM50VHA … PUZ-WM112YAA (OCH727 REVISED EDITION-A, 12/2023) (OCH727A (12/2023)) , p. 29 official manufacturer document quote verified
abnormal if following conditions are
- [3] Mitsubishi Electric – Service Manual: Air to water heat pump units, outdoor unit PUZ-WM50VHA … PUZ-WM112YAA (OCH727 REVISED EDITION-A, 12/2023) (OCH727A (12/2023)) , p. 29 official manufacturer document quote verified
1 leakage or shortage of
- [4] Mitsubishi Electric – Service Manual: Air to water heat pump units, outdoor unit PUZ-WM50VHA … PUZ-WM112YAA (OCH727 REVISED EDITION-A, 12/2023) (OCH727A (12/2023)) , p. 29 official manufacturer document quote verified
2 malfunction of linear expansion
- [5] Mitsubishi Electric – Service Manual: Air to water heat pump units, outdoor unit PUZ-WM50VHA … PUZ-WM112YAA (OCH727 REVISED EDITION-A, 12/2023) (OCH727A (12/2023)) , p. 29 official manufacturer document quote verified
3 clogging with foreign objects in
- [6] Mitsubishi Electric – Service Manual: Air to water heat pump units, outdoor unit PUZ-WM50VHA … PUZ-WM112YAA (OCH727 REVISED EDITION-A, 12/2023) (OCH727A (12/2023)) , p. 29 official manufacturer document quote verified
4 disconnection or contact failure
- [7] Mitsubishi Electric – Service Manual: Air to water heat pump units, outdoor unit PUZ-WM50VHA … PUZ-WM112YAA (OCH727 REVISED EDITION-A, 12/2023) (OCH727A (12/2023)) , p. 29 official manufacturer document quote verified
1 check intake superheat.
- [8] Mitsubishi Electric – Service Manual: Air to water heat pump units, outdoor unit PUZ-WM50VHA … PUZ-WM112YAA (OCH727 REVISED EDITION-A, 12/2023) (OCH727A (12/2023)) , p. 29 official manufacturer document quote verified
2 check linear expansion valve.
- [9] Mitsubishi Electric – Service Manual: Air to water heat pump units, outdoor unit PUZ-WM50VHA … PUZ-WM112YAA (OCH727 REVISED EDITION-A, 12/2023) (OCH727A (12/2023)) , p. 29 official manufacturer document quote verified
after recovering refrigerant, remove water
- [10] Mitsubishi Electric – Service Manual: Air to water heat pump units, outdoor unit PUZ-WM50VHA … PUZ-WM112YAA (OCH727 REVISED EDITION-A, 12/2023) (OCH727A (12/2023)) , p. 29 official manufacturer document quote verified
4 check short wiring connected to connector