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Error code reference

LG Cooktop Error Code FF

Right cooling fan failure.

LG codesLG cooktop codes

Right cooling fan failure.

First step from the service manual

Check CN 003 on filter board (Right); test the fan motor per page 33.

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

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What FF means on a LG cooktop

The FF error code on an LG cooktop indicates a failure detected in the right cooling fan circuit. Cooling fans in induction and electric cooktops are critical for dissipating heat generated by the inverter boards and power electronics during operation. When the control system detects that the right cooling fan is not operating within expected parameters, it triggers this code and typically shuts down or restricts cooktop operation to prevent thermal damage to internal components.

The primary diagnostic entry point is connector CN 003 on the right-side filter board. This connector carries the signal and power lines for the right cooling fan motor. A technician should inspect CN 003 for loose pins, corrosion, damaged wiring, or an improperly seated connector before proceeding further. If the connection appears intact, the next step is to test the fan motor directly according to the motor testing procedure, which involves checking for proper voltage supply and verifying motor winding continuity and resistance.

Common failure modes include a seized or open-circuit fan motor, a broken or disconnected wire harness, a failed filter board that is not supplying correct voltage to the fan, or debris obstructing the fan blade. Because the fan protects high-value power components, this error should not be bypassed or ignored. Operating the cooktop with a non-functional cooling fan risks overheating the inverter board and causing cascading component failures.

Source: manufacturer service documentation.

Common causes of FF

  1. 01

    Failed fan motor

    Part replacement

    The right cooling fan motor may have seized, burned out, or developed an open winding, preventing it from spinning. Testing the motor per the fan motor test procedure will confirm whether it is drawing current and operating correctly.

  2. 02

    Loose or damaged connector at CN 003

    Wiring / connection

    The connector CN 003 on the right filter board can work loose over time or suffer from corroded or bent pins, interrupting the signal or power to the fan. Visually inspect and reseat the connector, checking each pin for damage or oxidation.

  3. 03

    Broken or shorted wire harness

    Part replacement

    The wiring between CN 003 and the fan motor can develop breaks, chafing, or shorts, especially near stress points and heat sources. Continuity testing along the harness length will identify any open or shorted segment.

  4. 04

    Fan blade obstruction or debris

    Wiring / connection

    Foreign material such as grease buildup, food debris, or a dislodged component can physically block the fan blade and cause the motor to stall. Inspect the fan assembly for any obstructions and clear them before retesting.

  5. 05

    Right filter board not supplying voltage

    Part replacement

    If the filter board itself has failed, it may not be delivering the correct operating voltage to the fan motor through CN 003, causing the fan to remain inoperative. After confirming the fan motor and harness are good, verify output voltage at CN 003 from the filter board.

See the test procedure for each cause

Frequently asked questions about FF

What does FF mean on a LG cooktop?
The FF error code on an LG cooktop signals a failure in the right cooling fan circuit. The cooktop's control system has detected that the right cooling fan is not functioning as expected. This fan keeps critical internal electronics cool during operation, and the error is triggered to prevent thermal damage to the inverter board and other components.
Can I fix the FF error on my LG cooktop myself?
Some causes of the FF code, such as a loose connector at CN 003 on the right filter board or a debris-blocked fan blade, can be addressed by a knowledgeable DIYer comfortable working inside appliances. However, testing fan motor windings, checking board output voltage, or replacing the fan motor or filter board requires basic electrical testing skills and appropriate tools. If you are not comfortable working with appliance electronics, a qualified technician is recommended.
Is it safe to keep using my LG cooktop when the FF error is showing?
It is not safe to continue using the cooktop while the FF error is active. The cooling fan is responsible for preventing the internal electronics from overheating during operation. Running the cooktop without a functioning right cooling fan risks damaging the inverter board and other expensive internal components, and could create a fire hazard from excessive heat buildup.
Will resetting the cooktop clear the FF error code?
A power reset, such as turning off the circuit breaker for 30 to 60 seconds, may temporarily clear the FF code, but it will return as soon as the cooktop detects that the right cooling fan is still not operating correctly. The underlying hardware fault, whether a failed motor, damaged harness, or bad connector at CN 003, must be diagnosed and repaired for the code to clear permanently.
How much does it cost to repair the FF error on an LG cooktop?
Repair costs depend on the root cause. If only a connector needs reseating or a wiring harness needs repair, costs can range from a minimal service call fee up to around $100 to $200 for labor. Replacing the cooling fan motor typically adds $50 to $150 in parts. If the right filter board has failed, board replacement can bring total repair costs into the $200 to $400 or higher range, depending on labor rates and parts availability.

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