my induction cooktop makes a high-pitched humming or buzzing noise, is it broken?

Diagnosis

In the vast majority of cases, a high-pitched hum, buzz, or whine coming from your LG LREL6323S is not a sign of mechanical failure, but a physical phenomenon known as "magnetic resonance." Induction cooking works by passing a high-frequency alternating current through a copper coil beneath the glass ceramic surface. This creates a rapidly oscillating magnetic field that induces eddy currents in the base of your cookware. If the cookware is not perfectly rigid or is made of composite layers, these magnetic forces cause the metal layers to vibrate against each other at a high frequency, creating an audible sound. You can confirm this is normal operation by observing the noise level relative to the power setting. If the buzzing increases in pitch or volume when you engage the "Ultra Heat" or "Power Boost" modes, it is almost certainly resonance. Additionally, if the sound changes or disappears when you shift the pan slightly or change the cookware brand, the range's internal electronics are functioning correctly, and the issue lies in the interaction between the induction coil and the specific metallurgy of your pot.

How to Fix It

To eliminate or significantly reduce the buzzing sound, follow these precise steps to optimize the interaction between the range and your cookware:

1. Verify Cookware Material: Ensure you are using high-quality, heavy-bottomed induction-ready cookware. Avoid "induction-ready" pans that have a thin magnetic disc bonded to the bottom; these "clad" bottoms are prone to delamination and vibration. Opt for forged steel or cast iron, which are single-piece constructions and far quieter.
2. Check for Flatness: Place your pan on a completely flat surface (like a granite countertop) and press down on the edges. If the pan wobbles even a millimeter, the gap between the coil and the pan is uneven, which causes erratic magnetic flux and increased noise. Replace warped pans immediately.
3. Center the Load: Ensure the pan is perfectly centered on the cooking zone. The LREL6323S uses sensors to detect pan size; if the pan is off-center, the coil may struggle to maintain a consistent field, leading to a "stuttering" buzz.
4. Adjust the Power Level: If you are using a setting of 9 or 10 (or Power Boost), drop the setting to 7 or 8. The high-frequency oscillation is most aggressive at maximum power. Because induction is so efficient, a setting of 7 often provides more than enough heat for simmering or boiling without the acoustic stress.
5. Ensure Pan Size Match: Use a pan that matches the diameter of the ring. Using a 6-inch pan on a 10-inch element forces the range to cycle the power on and off rapidly to avoid overheating the empty sections of the coil, which creates a rhythmic clicking or buzzing sound.

If That Didn't Work

If the noise persists despite using high-end, flat, magnetic cookware, consider these alternatives:

• Test with Cast Iron: Try a heavy Lodge cast iron skillet. Because cast iron is a single, dense piece of metal, it almost never vibrates. If the cast iron is silent but your stainless steel is loud, the issue is definitely the construction of your stainless steel pans (specifically the bonding of the aluminum core to the steel exterior).
• Check for Loose Glass: While rare on the LREL6323S, check if the ceramic glass top is seated firmly. If the glass has shifted slightly on its gaskets, the internal cooling fans can cause the glass to vibrate. Gently press around the edges of the cooktop to see if the noise changes.
• Update Firmware: Since this is a Smart WiFi range, ensure your LG ThinQ app is updated and the range has the latest firmware. LG occasionally releases updates that optimize the PWM (Pulse Width Modulation) of the induction coils to reduce audible noise.
• Inspect for Debris: Ensure there is no metallic debris or foil trapped between the pan and the glass. Even a tiny piece of aluminum foil can vibrate violently in a magnetic field, creating a loud, sharp buzzing sound.

Heads Up

• Avoid "Power Boost" for Long Periods: Using the highest power settings frequently increases the thermal stress on the induction coil and maximizes noise levels.
• Clean the Surface Daily: Burnt-on food residue can create an uneven gap between the pan and the coil, which can amplify vibration and potentially scratch the glass.
• Avoid Sliding Pans: Always lift your pans. Sliding heavy cookware across the ceramic glass can create micro-scratches that affect the thermal transfer and can lead to glass failure over time.
• Magnetic Testing: If you aren't sure if a pan is truly induction-compatible, hold a strong fridge magnet to the bottom. If it doesn't snap firmly to the metal, it will either not work or produce significant noise.