LG Oven burning too intensely, fan has also quit

Oven/Range/Cooktop Repair
1

Brand:LG
Model Number:LSG4513ST
Main Symptom:oven burner too aggressive
What happens & when:When the oven is turned on, the oven burner seems to aggressive, blue flames shoot up which is causing the food in that area to burn. The oven fan has also quit working.

Error Code (if any):No error code
Parts or tests already tried:None
Photos / video link:

2

The two symptoms you’re seeing are very likely related.

On the LG LSG4513ST, the convection fan helps circulate heat throughout the oven. If that fan has stopped working, the heat from the bake burner is concentrated in one area instead of being distributed evenly. However, large blue flames shooting up from the burner are not considered normal, even with the fan inoperative.

Here are the most likely causes, starting with the easiest things to check:

1. Verify the Convection Fan Isn’t Running

Start the oven in a Convection Bake cycle.

After a minute or two, open the door briefly and listen or look through the rear vents to see if the convection fan is spinning. (The fan may cycle on and off, so give it a couple of minutes.)

If it never runs, unplug the range and:

  • Remove the rear oven panel inside the cavity to access the convection fan.
  • Check that nothing is blocking the fan blade.
  • Spin the blade by hand. It should turn freely without grinding or binding.
  • Inspect the wiring harness for loose or damaged connections.

If the fan spins freely, the next step is to test the fan motor for continuity with a multimeter. An open (OL) reading indicates the motor has failed and should be replaced.

2. Inspect the Bake Burner Flame

With the oven running, observe the bake burner.

A normal flame should be:

  • Mostly blue
  • Fairly even across the entire burner
  • Approximately 1/2 to 1 inch tall

If flames are shooting several inches into the oven or appear concentrated in one location, check for:

  • A burner that is not seated correctly over the gas orifice.
  • Debris, grease, or corrosion blocking some of the burner ports.
  • A warped or damaged bake burner causing uneven gas flow.

Clean the burner ports with a soft brush or wooden toothpick if necessary. Avoid enlarging the holes with metal objects.

3. Check the Gas Type

If this problem started after moving the range or performing service, verify that the range is configured for the correct fuel.

A range set up for LP (propane) but connected to Natural Gas, or vice versa, can produce abnormally large flames and poor baking performance.

4. Test the Convection Fan Circuit

If the fan motor tests good:

  • Restore power and start a convection cycle.
  • Live Power Warning: Extreme care should always be taken when testing live voltage. Electric shock can cause serious injury. If you’re not comfortable making live voltage measurements, skip this test.
  • Measure the voltage supplied to the convection fan motor. It should receive approximately 120 VAC when the control calls for the fan to run.
  • 120 VAC present but fan not running: Replace the convection fan motor.
  • No voltage present: Suspect a failed electronic control board or damaged wiring between the control and the fan.

A Few Questions

  1. Does this happen in Bake only, or also during Convection Bake?
  2. Is the range connected to Natural Gas or LP (propane)?
  3. Did the excessive flames begin around the same time the convection fan stopped working, or did one symptom appear before the other?

Those answers will help narrow down whether you’re dealing with a burner issue, a gas supply/configuration problem, or primarily a failed convection fan and control circuit.