Symptoms
- Lights stop dimming partway down instead of going very low or off
- Lights flicker or flash at the low end of the dimmer range
- Full brightness seems dimmer than the bulb's rated output
Likely causes
- CommonDimmer not designed for LED bulbsLED dimming curves differ from incandescent, and non-LED dimmers often can't dim them smoothly across the full range.
- CommonBulb not rated as dimmableNon-dimmable LED bulbs on a dimmer circuit will behave unpredictably, including a limited range.
- PossibleTotal wattage below the dimmer's minimum loadVery low-wattage LED loads can cause a dimmer to behave erratically at low settings.
- PossibleAn aging or worn dimmer mechanismDimmers can wear out and lose smooth range over years of use.
What to do
- Confirm your bulbs are labeled as dimmable, not just standard LEDs.
- Check the dimmer's compatibility and minimum wattage requirements against your bulbs.
- Try a small trim adjustment if your dimmer has a trim potentiometer for setting the low end.
- Replace with an LED-specific dimmer if the current one predates LED bulbs.
- Test with a different set of dimmable LED bulbs to rule out a bad batch.
- Have an electrician check the dimmer's wiring if a compatible dimmer and bulbs still don't dim smoothly.
Tools and parts
- Small screwdriver for trim adjustment
LED-compatible dimmer with trim adjustmentSearch: “LED dimmer switch with trim”
When to call a pro
Call an electrician if a properly matched dimmer and bulbs still won't dim through a full, smooth range.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.