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Error code reference

Fisher & Paykel Refrigerator Error Code INV-8

Compressor cannot start after 6 attempts.

Fisher & Paykel codesFisher & Paykel refrigerator codes

Compressor cannot start after 6 attempts.

First step from the service manual

Let compressor rest for 5 mins to allow pressure to equalise then try again.

The complete diagnostic procedure includes additional test steps, resistance specifications, wiring diagram references, and component test points.

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What INV-8 means on a Fisher & Paykel refrigerator

The INV-8 error code on a Fisher & Paykel refrigerator indicates that the inverter-controlled compressor has failed to start after six consecutive attempts. The inverter drive system regulates compressor speed and startup by carefully managing the electrical frequency and voltage delivered to the compressor motor windings. When the control board detects that the compressor has not reached operational speed after repeated startup sequences, it logs this fault and halts further attempts to protect the compressor from damage caused by repeated failed starts.

The most common reason for this fault is excessive refrigerant pressure trapped in the system, which creates a mechanical load too high for the compressor motor to overcome during startup. This is why the primary diagnostic step is allowing the compressor to rest for at least five minutes. During this rest period, the high-side and low-side refrigerant pressures equalize through the system, reducing the startup load to a level the motor can handle. This pressure imbalance is especially likely to occur after a recent power interruption or if the compressor was forced to restart shortly after shutting down.

If pressure equalization does not resolve the fault, the cause may be electrical or mechanical in nature. A failing compressor motor with degraded windings, a faulty inverter board unable to deliver correct startup signals, or poor electrical supply conditions such as low voltage can all prevent successful compressor starts. A refrigerant charge that is significantly out of specification, either overcharged or undercharged, can also produce abnormal pressure conditions that repeat the startup failure.

Source: manufacturer service documentation.

Common causes of INV-8

  1. 01

    High refrigerant pressure at startup

    Wiring / connection

    If the compressor stopped recently and restarts too quickly, pressure has not had time to equalize between the high and low sides of the system, creating excessive mechanical resistance. Allowing a 5-minute rest period before restarting is the recommended first step.

  2. 02

    Faulty inverter control board

    Part replacement

    The inverter board is responsible for generating the correct startup voltage and frequency signals to the compressor motor. A defective board may fail to deliver a proper start sequence, causing repeated startup failures even when refrigerant pressure is normal.

  3. 03

    Worn or failing compressor motor

    Part replacement

    Internal wear or degraded motor windings in the compressor can prevent it from generating enough torque to start under normal system pressures. This is typically identified by ruling out pressure and electrical supply issues first.

  4. 04

    Incorrect refrigerant charge

    Wiring / connection

    An overcharged or significantly undercharged refrigerant system can produce abnormal high-side pressure conditions that prevent successful startup. Diagnosis requires measuring system pressures with refrigeration gauges.

  5. 05

    Low or unstable supply voltage

    Wiring / connection

    Insufficient voltage to the inverter board can prevent the compressor from receiving adequate power during its startup sequence. Checking the supply voltage at the unit during a startup attempt can help identify this condition.

See the test procedure for each cause

Frequently asked questions about INV-8

What does INV-8 mean on a Fisher & Paykel refrigerator?
INV-8 means the refrigerator's inverter-controlled compressor failed to start after six consecutive attempts. The control system shuts down further startup attempts to protect the compressor from damage. This fault is most often triggered by high refrigerant pressure that builds up when the compressor is restarted too quickly after stopping. Allowing a 5-minute rest period to let system pressures equalize is the recommended first diagnostic step.
Can I fix an INV-8 error myself, or do I need a technician?
The first step, waiting five minutes for refrigerant pressure to equalize and then attempting a restart, is something any homeowner can safely do. If the error returns after that rest period, the fault likely involves the inverter board, compressor motor, or refrigerant charge, all of which require a qualified appliance technician with the proper tools and refrigerant handling certification.
Is it safe to keep using the refrigerator while it shows an INV-8 error?
When the INV-8 fault is active, the compressor is not running, meaning the refrigerator is not cooling. Food safety becomes a concern relatively quickly, especially in the freezer compartment. You should attempt the pressure equalization restart first, and if cooling does not resume, transfer perishable items to another cooled location while arranging for a service call.
Will resetting the refrigerator clear the INV-8 error?
A power reset by unplugging the unit for a few minutes may clear the fault code and allow the refrigerator to attempt another startup sequence. However, if the underlying cause has not been resolved, such as a faulty inverter board or a failing compressor, the INV-8 error will return after the next failed startup attempt. The rest period and power reset may work together if high refrigerant pressure was the only cause.
How much does it cost to repair an INV-8 error on a Fisher & Paykel refrigerator?
Repair costs depend entirely on the root cause. If the issue is simply high startup pressure and a rest period resolves it, there is no cost. An inverter board replacement typically ranges from $200 to $450 including parts and labor. Compressor replacement is significantly more expensive, often ranging from $400 to $800 or more depending on the model and local labor rates. A service call for diagnosis alone generally costs between $80 and $150.

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