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Error code reference

LG Oven Error Code H-3

Lower bake heater error detected during self-diagnosis.

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Lower bake heater error detected during self-diagnosis.

First step from the service manual

Check the lower bake heater wire on the Wall Main PCB (T206, T207) for correct connection.

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

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What H-3 means on a LG oven

The H-3 error code on an LG oven indicates that a lower bake heater fault has been detected during the oven's self-diagnosis routine. This self-diagnosis process runs automatically and monitors the integrity of heating circuits to confirm that each element is capable of drawing the expected current and completing its circuit properly. When the control system cannot confirm normal operation of the lower bake heater, it halts operation and stores the H-3 fault.

The lower bake heater circuit runs from the Wall Main PCB through a dedicated wiring harness to the bake element located at the bottom of the oven cavity. The PCB terminals T206 and T207 are the specific connection points associated with this heater circuit. A loose, corroded, or improperly seated connector at either of these terminals is the first area to inspect, as a poor connection here will interrupt the circuit signal and trigger the fault even if the element itself is undamaged.

Beyond the connector at the PCB, the fault can also originate from a failed bake element, damaged wiring between the board and the element, or a failure within the Wall Main PCB itself. The bake element can fail by burning open, which creates a complete break in the circuit, or by shorting internally. Visible signs of element failure include blistering, burn marks, or a visible break in the element surface. Wire harness damage from heat exposure over time is also a contributing factor in older units.

Source: manufacturer service documentation.

Common causes of H-3

  1. 01

    Loose or disconnected wiring at PCB terminals T206/T207

    Wiring / connection

    A connector that has worked loose or is improperly seated at terminals T206 or T207 on the Wall Main PCB will interrupt the circuit and trigger H-3. Inspect these terminals first and reseat any connectors that show signs of looseness or corrosion.

  2. 02

    Failed lower bake element

    Part replacement

    The bake element itself may have burned open or shorted internally, breaking the circuit the control board is monitoring. Visually inspect the element for blistering, burn marks, or a visible break, and test continuity with a multimeter.

  3. 03

    Damaged wiring harness between PCB and bake element

    Part replacement

    The wire harness running from the Wall Main PCB to the lower bake element can sustain heat damage over time, causing broken conductors or melted insulation that interrupts the circuit. Inspect the full length of the harness for visible damage.

  4. 04

    Corroded or burnt connector terminals

    Wiring / connection

    Even if the connector is physically seated, corrosion or heat-related oxidation on the terminals at T206 or T207 can create enough resistance to cause a circuit fault. Check the terminal pins closely for discoloration or buildup.

  5. 05

    Faulty Wall Main PCB

    Part replacement

    If the wiring, connectors, and bake element all test as functional, the Wall Main PCB itself may have an internal failure affecting how it reads or drives the lower heater circuit. Board replacement is typically a last-resort diagnosis after ruling out all other components.

See the test procedure for each cause

Frequently asked questions about H-3

What does H-3 mean on a LG oven?
H-3 on an LG oven means the control system detected a fault with the lower bake heater circuit during its self-diagnosis routine. The oven was unable to confirm that the lower bake element and its associated wiring are functioning correctly. This error prevents normal baking operation until the underlying issue is identified and corrected.
Can I fix the H-3 error myself, or do I need a technician?
Some causes of H-3 are within reach of a knowledgeable DIYer. Checking and reseating the wire connectors at terminals T206 and T207 on the Wall Main PCB requires only basic tools and no special skills. However, testing and replacing the bake element or wiring harness involves working near high-voltage components, and board replacement requires careful handling. If you are not comfortable working with electrical components inside an oven, a qualified technician is the safer choice.
Is it safe to use my LG oven while the H-3 error is displayed?
No, you should not attempt to use the oven while H-3 is active. The error indicates a fault in the lower heating circuit, which means the oven may not heat correctly or at all, and an undiagnosed wiring or element problem can pose a risk of further damage or a potential electrical hazard. Leave the oven off until the fault is diagnosed and repaired.
How much does it cost to repair an H-3 error on an LG oven?
Repair costs depend on the root cause. If only a loose connector needs reseating, there may be no parts cost at all, though a service call typically runs between $75 and $150. A replacement lower bake element generally costs between $25 and $80 for the part itself. If the Wall Main PCB requires replacement, parts and labor combined can range from $200 to $400 or more depending on the model and labor rates in your area.
Will resetting the oven clear the H-3 error code?
Resetting the oven by cycling the power at the breaker may temporarily clear the H-3 code, but it will return if the underlying fault is still present. Because H-3 is triggered by the oven's self-diagnosis routine, the code will reappear as soon as the oven runs that check again. A permanent fix requires identifying and correcting the actual fault in the lower bake heater circuit.

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