57 on a Mitsubishi Heavy Industries Air-Conditioning Europe Hydrolution: Erroneous software: The heat pump's program and serial number do not match each other
Short answer
On a Mitsubishi Heavy Industries Air-Conditioning Europe heat pump, 57 means: Erroneous software: The heat pump's program and serial number do not match each other. The heat pump stops until the fault clears or is reset. An engineer is needed to fix the cause.
Reviewed 23 September 2026 · 1 source
What it means
The manual says: Erroneous software: The heat pump's program and serial number do not match each other.
Part involved: Erroneous software.
When it shows: The heat pump's program and serial number do not match each other.
Likely causes:
- Incorrect software installed.
Is it safe?
| Does the heat pump stop? | Yes |
|---|---|
| Severity | Fault — needs a manual reset once the cause is fixed |
| Engineer needed? | Yes |
The heat pump stops until the fault clears or is reset.
Resetting itself: no.
Manual reset: yes (select 'reset alarm' in the alarm menu).
What you can check
- Note the alarm number/text shown on the display. Check the consumer-unit breakers/isolators for the indoor and outdoor units are on. On the RC-HY controller you may select 'reset alarm' once (installation manual: 'in most cases it is enough'); if the red lamp stays or the alarm returns, select 'aid mode' (if enabled) or 'add. heat only' in menu 4.2 and contact the installer.
What the engineer will check
- Per manual 'May be due to': Incorrect software installed. Check sensor wiring/resistance, settings, flow (particle filter, pump) and supply as applicable.
Who to ask for: Heat pump / refrigeration engineer (manufacturer-trained).
Certification: F-gas certification for refrigerant-circuit work; electrical competence (Part P/18th Edition) for PCB/wiring.
What you might notice
Sources
- Installation Manual - Air to Water Heat Pump using R32 refrigerant, Hydrolution (HM) ↗ · PSC012D169 (202201) · page PDF p.78 (printed 76) · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026