Why Is My Lutron Caseta Dimmer Buzzing or Humming

Problem Description

Your Lutron Caseta dimmer buzzes audibly from the switch body or the connected light bulbs hum when dimmed below full brightness. The noise increases at specific dim levels and may be more pronounced with certain bulbs. This is a load compatibility issue between the Caseta dimmer and the LED bulb's internal driver circuit — not a defective dimmer.

Symptoms

• Buzzing from dimmer switch
• Humming from light bulbs
• Noise at specific dim levels
• Worse at 50% brightness
• Silent at full bright
• Bulbs flicker with buzz

Recognize these? Here's what usually causes it.

Common Causes

• Incompatible LED bulbs
• Bulbs not dimmable rated
• Too few bulbs on dimmer
• Low-end trim set wrong
• Bulb driver resonating
• Dimmer overloaded

Tools & Requirements

Step-by-Step Solution

1

Verify Bulbs Are on the Lutron LED Compatibility List

Go to lutron.com and use the LED Compatibility Checker to confirm your specific LED bulbs are tested and listed for your Caseta dimmer model. Buzzing and flicker with LED bulbs is almost always a load compatibility issue, not a dimmer defect. Replace incompatible bulbs with listed alternatives — Philips, GE, Cree, and Feit bulbs from the compatibility list work reliably with Caseta dimmers. Even one incompatible bulb on a multi-bulb circuit causes audible buzzing.

2

Confirm All Bulbs Are Marked Dimmable

Check the packaging or product page for every bulb on the circuit and confirm each is explicitly rated as dimmable. Non-dimmable LEDs connected to a dimmer buzz, flicker, and are damaged by the dimmed voltage waveform over time. Replace any non-dimmable bulb with a dimmable equivalent. A single non-dimmable bulb mixed into a circuit with dimmable bulbs causes the entire load to behave erratically.

3

Adjust the Low-End Trim to Eliminate Low-Level Flicker

Hold the Caseta dimmer paddle in the fully off position for approximately 4 seconds until the LED indicator flashes. The dimmer enters low-end trim adjustment mode. Press the top of the paddle to raise the minimum dim level, or the bottom to lower it. Raise it until flickering at low brightness levels stops. Press the paddle once to exit and save. This calibrates where the dimmer's waveform begins driving the LED driver circuit, eliminating the instability range.

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4

Add Bulbs to Reach Minimum Load

Lutron Caseta dimmers have a minimum load requirement. If you are only dimming 1 or 2 LED bulbs with a total wattage below 5W, the dimmer is operating below its minimum load threshold and will buzz. Add another bulb to raise the total circuit wattage, or replace the dimmer with the Lutron PD-6WCL which supports a 0W minimum load, specifically designed for low-count LED installations.

5

Check for Loose Wiring at the Switch

Buzzing that occurs from the switch body itself (not the bulbs) can indicate a loose wire connection at the dimmer terminals. Turn off the circuit breaker, remove the Caseta dimmer from the wall box, and inspect all wire connections. Ensure each wire is fully seated in its terminal with no exposed copper outside the connector. Tighten any push-in connectors or retighten screw terminals. Reinstall and test — loose wiring causes resistive heating that produces buzzing from the switch chassis.

Quick Solutions

Still having issues? This is usually the deeper cause below.

Need More Help? Lutron Support

Note: The contact information below connects you directly to Lutron's official customer support team, not Trunetto. They can help with warranty claims, device replacements, and advanced technical issues.