LG Oven F5 Error: Relay board failure
LG oven error — here’s what you need to know. The F5 error code on your LG oven indicates control board relay failure. This is a High severity issue. What Does F5 Mean on an LG Oven? The F5 error code means the oven control board has detected a failure in one of its internal […]
~30%
DIY Fixable
From 00
Typical Repair Cost
60–120 min
Pro Repair Time
Quick Assessment
Answer to continue safely
Is it safe to keep using?
No. Do not use the oven. A welded relay contact can cause an element to stay on indefinitely, creating a serious fire hazard. An open relay prevents safe temperature regulation.
Can I reset the code?
Yes. F5 is a hardware failure — burned or welded relay contacts cannot be fixed by resetting power. The faulty board must be repaired or replaced.
When to stop immediately?
Stop if you notice: Stop and turn off the circuit breaker immediately if you smell burning from the oven area., Stop if the oven continues to heat after you press Cancel — a welded relay may be present..
Symptoms You May Notice
Bake or broil element does not heat despite the oven appearing to run
The display shows an active cooking cycle and counts down the timer, but the oven cavity remains at room temperature because the relay cannot complete the circuit to the element.
F5 code on the display
The oven shows F5 on the display, typically with beeping; the code may appear at startup, during preheating, or at a specific point in a cooking cycle.
Burning smell from behind the control panel or inside the oven
A welded relay contact keeping an element continuously energized can cause heat to build up in unexpected areas, producing a burning smell before F5 is displayed.
Intermittent or unresponsive controls
Buttons or display elements stop responding, flicker, or behave erratically because signals between the control boards are disrupted or corrupted.
Possible Causes
Worn or welded relay contacts on the control board
Years of high-current switching have pitted or welded the relay contacts, causing them to either fail open (no heat) or weld closed (element stays on permanently).
Requires ProfessionalFailed heating element causing relay overcurrent
A shorted bake or broil element draws excessive current through the relay contacts, accelerating their failure and triggering F5.
DIY PossibleFaulty relay board (on models with separate relay board)
On LG wall oven models that use a separate relay board, the board itself has failed and is no longer correctly switching power to the oven elements.
Requires ProfessionalSafe Checks You Can Do
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1
Power cycle and note when F5 appears
Reset the oven by turning off its circuit breaker for 60 seconds. Restore power and note whether F5 appears immediately at startup (board-level fault) or only when the oven is asked to heat (relay switching failure).
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2
Check the bake and broil elements for visible damage
With the oven off and unpowered, visually inspect the bake element (bottom of oven) and broil element (top) for blistering, cracks, or burn-through that would indicate a failed element causing excessive current draw.
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3
Listen for relay click sounds
When the oven tries to start heating, listen for the audible click of relays switching inside the control panel area. No click at all suggests the board is not sending the switching command, while a click with no heat suggests the relay contacts have failed open.
When to Call a Professional
Contact a qualified technician if:
- Oven elements remain energized after pressing Cancel.
- Burn marks or heat damage are visible on the relay board.
- Control board or relay board replacement is required.
Need Professional Help?
Find qualified technicians in your area for proper diagnostics and repair.
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