P14 on a Grant Aerona 290: Refrigerant leakage fault

What it means

The manual says: Refrigerant leakage fault.

Part involved: refrigerant leakage sensor / hydraulic PCB.

Likely causes:

• Leak in refrigerant circuit.
• Refrigerant leakage sensor failure.
• Hydraulic PCB is faulty.

Is it safe?

Switch the heat pump off at its isolator and call an engineer.

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

Resetting itself: Not stated in DOC 0204.

Manual reset: DOC 0204 s11.1: once the fault is resolved, reset by turning the unit OFF and back ON; s11.5: power cycle can be done from the Aerona Smart Controller touchscreen instead of the external isolator (installer procedure).

What you can check

• Note the exact code shown on the controller display and tell your installer or Grant-trained engineer.
• Leave the heat pump switched off at the controller and call an engineer; keep ignition sources away from the outdoor unit and do not open the casing (R290 is flammable).
• Check the heat pump isolator switch and the consumer-unit breaker/RCD for the heat pump are ON (do not repeatedly reset a tripping breaker).

What the engineer will check

• Check for leakage in refrigerant circuit and repair.
• Check refrigerant leakage sensor; replace if faulty.
• Check hydraulic PCB; replace if faulty.

Who to ask for: Grant-trained heat pump engineer.

Certification: F-gas certified engineer also trained/competent for flammable A3 refrigerant R290 (propane).

What you might notice

• No heating
• No hot water

Sources

• Grant Aerona 290 Air to Water Air Source Heat Pump Range - Installation & Operating Instructions (UK DOC 0204) ↗ · Rev 1.9 · page 55 · Reviewed 23 September 2026

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

Reviewed: 23 September 2026