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Error code reference

KitchenAid Cooktop Error Code F-42

Power supply issue

KitchenAid codesKitchenAid cooktop codes

Power supply issue — incorrect or missing voltage at the power control board or EMI filter board.

First step from the service manual

Check for 240 VAC at the main incoming power supply connection.

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

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What F-42 means on a KitchenAid cooktop

The F-42 error code on a KitchenAid cooktop indicates a power supply fault, specifically that the power control board or EMI (electromagnetic interference) filter board is detecting incorrect or missing voltage at its incoming supply. These cooktops require a properly balanced 240 VAC two-leg supply to operate correctly. If either leg of the supply is absent, undersized, or out of specification, the control system will flag this fault and disable operation to prevent damage to internal components.

The power control board and EMI filter board are the first points of entry for line voltage inside the unit. The EMI filter board conditions incoming AC power before it reaches the control electronics, suppressing electrical noise that could cause interference. If this board receives malformed input voltage, or if the power control board does not see the expected 240 VAC across both legs, the F-42 code is triggered. Common root causes include a tripped or failed double-pole circuit breaker, a loose or corroded terminal connection at the junction box, a wiring fault in the supply cable, or an internal failure of the EMI filter board or power control board itself.

Diagnosis should begin at the main incoming power supply connection, where a multimeter should confirm 240 VAC across both hot legs and approximately 120 VAC from each leg to neutral. If supply voltage is correct at the terminal block but the error persists, attention should shift to the wiring and connectors between the terminal block and the EMI filter board, and then to the boards themselves.

Source: manufacturer service documentation.

Common causes of F-42

  1. 01

    Tripped or failed circuit breaker

    Wiring / connection

    A double-pole 240 VAC breaker that has partially or fully tripped will remove one or both legs of supply voltage. Check the breaker panel for a tripped breaker and test the breaker output with a multimeter to confirm it is delivering full 240 VAC.

  2. 02

    Loose or corroded supply wiring at the terminal block

    Wiring / connection

    A loose connection at the cooktop's incoming terminal block can cause one leg of the 240 VAC supply to drop out under load. Inspect all terminal screws for tightness and look for signs of arcing, discoloration, or corrosion.

  3. 03

    Faulty or damaged supply cable

    Part replacement

    A damaged 240 VAC supply cable with a broken conductor or compromised insulation can interrupt one leg of power before it reaches the unit. Inspect the cable for visible damage and verify continuity on each conductor.

  4. 04

    Failed EMI filter board

    Part replacement

    If incoming supply voltage tests correctly but the F-42 fault remains, the EMI filter board may have failed internally and is not passing proper voltage to the control board. The board will need to be tested and likely replaced.

  5. 05

    Failed power control board

    Part replacement

    A power control board that has failed internally may not correctly detect or process the incoming 240 VAC supply, generating the F-42 code even when line voltage is present and correct. Board replacement is required if all upstream components test within spec.

See the test procedure for each cause

Frequently asked questions about F-42

What does F-42 mean on a KitchenAid cooktop?
F-42 indicates a power supply fault where the power control board or EMI filter board is detecting incorrect or missing voltage from the 240 VAC supply. The cooktop requires a properly balanced two-leg 240 VAC input to operate. This code can be caused by a tripped breaker, a loose wiring connection, a damaged supply cable, or a failed internal board. The unit will not function until the fault is resolved.
Can I fix a KitchenAid cooktop F-42 error myself?
Some causes of F-42 are accessible to a knowledgeable DIYer, such as resetting a tripped circuit breaker or tightening a loose terminal connection at the cooktop's junction box. However, any work involving 240 VAC wiring or internal board replacement carries serious electrical safety risks and should only be performed by someone comfortable working with high-voltage appliances. If you are not experienced with electrical diagnostics, hiring a licensed technician is the safer choice.
Is it safe to use my KitchenAid cooktop while F-42 is displayed?
No. The F-42 code indicates the cooktop is not receiving correct power, and the unit will typically disable itself to prevent damage. Attempting to operate the cooktop under these conditions is not safe. The underlying power supply issue should be diagnosed and corrected before resuming use.
Will resetting my KitchenAid cooktop clear the F-42 error?
A power reset by turning off the circuit breaker for 30 seconds and restoring power may temporarily clear the code, but it will return if the underlying power supply fault has not been corrected. F-42 is not a soft error that resolves on its own. A reset is useful only as a diagnostic step to confirm whether the fault is intermittent or consistent, not as a repair.
How much does it cost to repair a KitchenAid cooktop showing F-42?
Repair costs vary widely depending on the root cause. If the fix is simply resetting a tripped breaker or tightening a connection, the cost is minimal. Replacing a supply cable or internal board typically involves both parts and labor, with total repair costs commonly ranging from $150 to $450 or more depending on the specific parts needed and local labor rates. Getting a diagnostic estimate from a technician before authorizing board replacement is advisable.

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