Why are my Dimmer Lights Flickering?

Causes of Flickering Lights

Before knowing how to solve your flickering lights, you’ll have to determine the cause. Luckily, sometimes when your lights are flickering, there is an easy way to fix it. It can be as simple as a loose connection or bulb, which simply requires tightening. In other scenarios, your lighting controls might not be properly calibrated.

Incompatible light bulb and dimmer switch

If you’re having a flickering issue on a dimmer switch, there is possibly a compatibility issue between the light bulb and the dimmer switch. There are a few things to check:
•    The light bulb is listed as dimmable.
•    The dimmer switch is compatible with the light bulbs you are using whether they are LEDs, halogen or incandescent. 
•    The dimmer switch is rated for the same voltage as the lighting. 
•    The total wattage of all bulbs/fixtures is less than or equal to the maximum wattage rating on the dimmer switch. 
•    If flickering occurs at the minimum dim level, consider increasing the minimum dim level above the level at which flickering occurs.

Loose connection

A loose connection poses a potentially more significant danger and is more complicated to diagnose. Start by checking on loose light bulbs and making sure that each bulb and socket is screwed-in tightly. If that doesn’t resolve the issue, there might be a larger problem at hand. This is a good time to contact an electrician to examine the issue further.

Overloaded Circuit

An overloaded circuit is caused by too many appliances being plugged in and running at once. If your flickering lights are consistent, severe and persistent when an appliance turns on, it may be worth checking into.

Environmental Interference on a Circuit

Flickering may be caused by environmental interference on a circuit, fluctuations/spikes in the line voltage or problems with neutral wiring. If a neutral connection is available in the box, a 3-wire or neutral required dimmer can help mitigate these issues.

What is Forward Phase vs. Reverse Phase Dimming?

Dimmable LEDs typically operate with either forward-phase dimming or reverse-phase dimming. Most bulbs and recessed lighting fixtures use forward phase dimming (also referred to as leading edge or TRIAC dimming). Many other LED fixtures require reverse phase dimming (also commonly referred to as trailing edge, or ELV - electronic low voltage dimming). If flickering is happening, it's possible that the incorrect dimmer type is being used. It's important to understand the lighting specs or the LED driver information for the required dimming type.

Note: The radiant® LED Advanced dimmer is a forward-phase dimmer and the Tru-Universal is a forward- and reverse-phase dimmer.

Why are my LED lights flickering?

LED Lights are known to be more prone to flickering, as they are more sensitive to voltage changes. It’s possible the LED bulb isn’t compatible with the dimmer switch, or that it’s not calibrated properly. Install a high-quality dimmer switch with a wattage rating that meets or exceeds the total wattage of all the light bulbs or fixtures you need to control. Be sure that the dimmer switch is LED compatible like the radiant® LED Advanced Dimmer or the Tru-Universal Dimmer.

When do I need to contact an electrician?

If your lights are flickering and you’ve determined that it is not related to an issue with the light bulb, an overloaded circuit, or is incompatible with your dimmer switch, it may be time to call a professional. It’s important to know your expertise and comfort level when dealing with electrical safety and it’s always best to err on the side of caution.

Why are my lights flickering on the low end of the dimming range?

Many LED bulbs and fixtures are only designed to be dimmed to a certain level on the low end, also known as minimum dim level (ex. dimming down to 5%, 10% 20% brightness). In many cases, a dimmer (as programmed out of the box) will try to dim the lights lower than the level they are designed for which can cause flickering. To fix this, many dimmers (like the radiant® LED Advanced dimmer) offer built-in manual adjustment of the low-end dimming range. By re-setting this level to be above the point at which flickering is seen, the problem can be cut out of the dimming range.

Why are my track lights flickering?

If the LED lighting has an external power transformer, it may be magnetic low voltage (MLV) or electronic low voltage (ELV), which is common with specialty lighting like track lighting, tape and tube lighting, and cove or accent lighting. If this is the case, a dimmer MUST be rated for these MLV and ELV callouts to properly work. A dimmer that just says LED:150W or LED:250W is not rated for these applications unless specifically called out, even if the lighting is technically LED.