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Error code reference

Whirlpool Cooktop Error Code F-42

Power supply issue

Whirlpool codesWhirlpool 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 volts AC at the main incoming power supply connection at J1 L to N and J2 L to N at the EMI filter board, and J1 L to N at both power control boards.

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 Whirlpool cooktop

The F-42 error code on a Whirlpool cooktop indicates a power supply problem, specifically that the power control board or EMI filter board is detecting incorrect or absent voltage at one or more of its supply connections. This code points directly to the electrical supply side of the cooktop's control system rather than a sensor or cooking element fault. The EMI filter board serves as the first point of entry for incoming AC power, filtering electromagnetic interference before voltage is distributed to the power control boards that manage heating zones and electronic controls.

The diagnostic process focuses on verifying 240 volts AC at specific connection points: terminals J1 L to N and J2 L to N on the EMI filter board, and J1 L to N on each of the power control boards. A 240-volt cooktop requires two 120-volt legs from the supply panel, and a loss or imbalance on either leg will prevent the boards from receiving proper voltage. This means the problem could originate at the household breaker panel, in the supply wiring, at the wall receptacle or hardwire connection, or within the internal wiring and board connectors of the cooktop itself.

Common root causes include a tripped or weakened circuit breaker supplying only one leg of the 240-volt circuit, loose or corroded wiring connections at the terminal block or junction box, a failed EMI filter board that is not passing voltage through to the control boards, or damaged internal wiring harnesses between the boards. Component failure on one of the power control boards can also produce this code if the board's internal circuitry is drawing the supply voltage out of the expected range.

Source: manufacturer service documentation.

Common causes of F-42

  1. 01

    Tripped or weak circuit breaker

    Wiring / connection

    A partially tripped double-pole breaker can drop one of the two 120-volt legs, resulting in only 120 volts reaching the cooktop instead of the required 240 volts. Reset the breaker fully by switching it off then on, and check both legs for proper voltage at the panel.

  2. 02

    Loose or corroded supply wiring connections

    Wiring / connection

    Loose terminals at the cooktop's junction box or wall connection point can cause voltage drop or a complete loss of one supply leg. Inspect the incoming wire connections for signs of arcing, corrosion, or looseness at the terminal block.

  3. 03

    Failed EMI filter board

    Part replacement

    If incoming supply voltage is confirmed at 240 volts AC at J1 and J2 on the EMI filter board but is absent on the output side feeding the power control boards, the EMI filter board itself has likely failed and needs replacement.

  4. 04

    Damaged or disconnected internal wiring harness

    Wiring / connection

    Wiring harnesses connecting the EMI filter board to the power control boards can suffer heat damage, connector loosening, or physical damage over time. Inspect all connectors and wiring runs between boards for continuity and secure seating.

  5. 05

    Failed power control board

    Part replacement

    If voltage is present at the power control board input connector J1 but the board is still triggering F-42, the board's internal circuitry may have failed. This would require replacement of the affected power control board.

See the test procedure for each cause

Frequently asked questions about F-42

What does F-42 mean on a Whirlpool cooktop?
F-42 indicates that the cooktop has detected an incorrect or missing voltage at the power control board or EMI filter board. The cooktop requires a proper 240-volt AC supply, and if either supply leg is absent or out of range, this code will appear. The fault can originate in the home's electrical supply or within the cooktop's internal power distribution components.
Can I fix the F-42 error on my Whirlpool cooktop myself?
Some steps, such as resetting a tripped circuit breaker, are safe for a homeowner to attempt. However, verifying 240-volt AC at specific board connectors inside the cooktop requires a multimeter, electrical knowledge, and safe working practices around live circuits. Internal board replacement should be handled by a qualified technician if you are not experienced with appliance electrical repair.
Is it safe to use my Whirlpool cooktop while the F-42 code is showing?
No, you should not attempt to use the cooktop while F-42 is active. The code indicates a fundamental power supply problem that prevents the cooktop from operating correctly. Continuing to use the appliance under these conditions risks further damage to the control boards or a potential electrical hazard.
Will resetting my Whirlpool cooktop clear the F-42 error code?
A reset by cycling the circuit breaker off and back on may clear the code temporarily if the cause was a transient power disturbance or a tripped breaker. However, if the underlying cause is a failed board, damaged wiring, or a persistent supply voltage problem, the code will return as soon as the cooktop attempts to power on again.
How much does it cost to repair a Whirlpool cooktop showing an F-42 error?
Repair costs vary depending on the cause. If only a circuit breaker reset or wiring tightening is needed, costs can be minimal. Replacing an EMI filter board or a power control board typically involves parts costs ranging from roughly $80 to $250 or more per board, plus labor if a technician is needed. Diagnosing the exact failed component first will help avoid unnecessary parts replacement.

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