the oven on my lrel6323s takes forever to preheat, like 30 minutes to hit 350, is this normal?

Diagnosis

The LG LREL6323S is designed to reach 350°F in approximately 12 to 15 minutes under normal operating conditions. If your unit is taking 30 minutes or more, you are experiencing a significant loss of thermal efficiency. This is typically caused by a "partial failure" of the bake element. Unlike a total burnout where the oven stays cold, a partial failure occurs when the internal resistive wire develops a high-resistance spot or a hairline fracture. This allows the element to still produce heat, but at a fraction of its intended wattage, meaning it cannot overcome the heat loss of the oven cavity quickly enough to raise the temperature. Another common culprit for this specific model is a drifting oven temperature sensor (RTD). The sensor is a thermistor that tells the control board the current internal temperature. If the sensor has drifted out of calibration, it may "trick" the board into thinking the oven is hotter than it actually is, causing the heating element to cycle off prematurely. You can confirm a failing element by turning the oven to "Bake" and visually inspecting the lower coil after 5 minutes; if there are "cold spots" or sections that are not glowing a consistent dull red, the element is compromised. If the element glows evenly but the temperature climbs at a snail's pace, the sensor is the likely failure point.

How to Fix It

To resolve a failing bake element, you must replace the lower heating assembly. For the LREL6323S, this is typically a 240V tubular element.

1. Disconnect the range from the power source by unplugging it or flipping the 40-amp circuit breaker in your electrical panel.
2. Open the oven door and remove the oven racks and the bottom heating element cover/guard if your specific sub-model has a removable floor plate.
3. Locate the two screws securing the element flange to the oven wall. Use a nut driver or screwdriver to remove these screws.
4. Carefully pull the element forward. Once the element is slightly out of the oven cavity, locate the wiring harness. Depress the locking tab on the plastic connector and pull the wires apart.
5. Slide the old element completely out of the oven.
6. Install the new element by sliding the terminals into the oven wall first, then connecting the wiring harness until you hear a distinct click.
7. Align the flange with the mounting holes and tighten the screws firmly, but do not over-tighten to avoid stripping the oven wall threads.
8. Reinsert the racks and power the unit back on. Run a test cycle to 350°F and time the preheat process.

If That Didn't Work

• Replace the Oven Temperature Sensor: If the element is glowing red but the heat isn't rising, the sensor (located in the upper back corner of the oven) is likely sending incorrect resistance readings. Remove the two screws holding the sensor probe, unplug the wire harness, and install a new LG-compatible RTD sensor.
• Check the Oven Door Gasket: Inspect the fiberglass and rubber seal around the oven door. If the gasket is torn or compressed (leaving gaps), hot air escapes as fast as the element can produce it. Feel for drafts around the edges while the oven is warming; if you feel a breeze, replace the door seal.
• Test the Control Board Relay: In rare cases, the relay on the main PCB (Printed Circuit Board) may be sticking or failing, causing the element to pulse on and off irregularly rather than staying on continuously during the preheat phase. This requires a multimeter to check for consistent 240V output at the element terminals.
• Verify Calibration Settings: Access the "Oven Offset" menu in the settings. If a previous owner set a significant negative offset (e.g., -35°F), the oven may behave erratically during the preheat climb. Reset the oven calibration to zero.

Heads Up

• Avoid "Cold-Starting" the Broiler: Never use the broiler setting to speed up the preheat of the bake section; this can warp the oven ceiling or damage the upper element.
• Clean the Element: Avoid using harsh chemical oven cleaners directly on the bake element coils, as this can accelerate the oxidation of the sheath and lead to premature burnout.
• Power Cycle: If the WiFi smart features seem to be lagging or the display is glitching during preheat, perform a hard reset by flipping the breaker for 60 seconds to clear the logic board cache.
• Ventilation: Ensure the range is pushed back correctly but not jammed against the wall, as poor airflow to the rear chassis can occasionally affect the thermal regulation of the control board.