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Heat pumps · Error codes · Kensa
LPKensa

LP on a Kensa heat pump: Low gas (refrigerant) pressure in machine; can occur with A1

Short answer

On a Kensa heat pump, LP means: Low gas (refrigerant) pressure in machine; can occur with A1. The heat pump stops until the fault clears or is reset. An engineer is needed to fix the cause.

Reviewed 23 September 2026 · 7 sources

What it means

The manual says: Low gas (refrigerant) pressure in machine; can occur with A1.

Part involved: Suction pressure / ground flow.

When it shows: Legacy panel controller: 'Display flashes fault code LP'.

Likely causes:

  • Ground pump not operating, first start-up or long idle, insufficient antifreeze and frozen unit (Plantroom: blocked filters).

Is it safe?

Does the heat pump stop?Yes
Engineer needed?Yes

The heat pump stops until the fault clears or is reset.

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

  • Check water pumps and impellers, antifreeze concentration; defrost if frozen; contact Kensa if persists (possible refrigerant issue).

Who to ask for: Refrigeration engineer (F-gas certified) / Kensa technical support.

Certification: F-gas Category I if refrigerant circuit opened; MCS GSHP installer.

What you might notice

Sources

A code explains what the controller detected, not a confirmed root cause.

Reviewed: 23 September 2026