LP2 on a Kensa heat pump: Low refrigerant pressure in suction gas pipe (P4), twin only
Short answer
On a Kensa heat pump, LP2 means: Low refrigerant pressure in suction gas pipe (P4), twin only. The heat pump keeps running with some functions stopped. An engineer is needed to fix the cause.
Reviewed 23 September 2026 · 2 sources
What it means
The manual says: Low refrigerant pressure in suction gas pipe (P4), twin only.
Part involved: P4 suction pressure (compressor 2).
When it shows: Error level per manual: Fault.
Likely causes:
- Ground-side flow restriction (often with FGH2), frozen unit / insufficient antifreeze, ground pump failure.
Is it safe?
| Does the heat pump stop? | Partly |
|---|---|
| Engineer needed? | Yes |
The heat pump keeps running with some functions stopped.
Resetting itself: unknown.
Manual reset: unknown.
What you can check
- Note the code shown on the controller/LED; check the heat pump isolator and consumer-unit breaker are on; check thermostat/timer settings.
What the engineer will check
- Follow Kensa fault table actions: Ground-side flow restriction (often with FGH2), frozen unit / insufficient antifreeze, ground pump failure.
Who to ask for: Refrigeration engineer (F-gas certified) / Kensa technical support.
Certification: F-gas Category I (refrigerant circuit work); MCS-certified GSHP installer.
What you might notice
Sources
- Q80 Series Heat Pump Operational Manual ↗ · Version 2 · page 24 · Reviewed 23 September 2026
- Shoebox Heat Pump Operational Manual (User Manual) ↗ · Version 8 · page 27 · Reviewed 23 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 23 September 2026