Info Leonlite

Apr 18, 2023 

How to Fix Dimmable LED Lights Flash and Flicker

How to Fix Dimmable LED Lights Flash and Flicker

How to Fix Dimmable LED Lights Flash and Flicker

LED dimmer light flicker can occur due to various reasons, and it's essential to identify the root cause to fix the issue. We has been resolving this problem for our clients and homes for years.

We will share our top 19 tips to investigate and resolve dimmable LED flash.

Let's begin by exploring the primary reasons for flickering LED lights, which are the most common causes that need to be addressed.

Top 5 Causes of Dimmable LED Light Flickering & Flashing

If your LED lights flicker when dimmed, it's likely due to one of these top 5 reasons behind dimmable lights flashing.

1. Unsecured Wiring

LED lights flickering intermittently could be a result of a simple installation issue. Unsecured wiring is among the most frequent problems encountered. Any unsecured wires will need to be reconnected or tightened.

It's recommended to have an expert examine your wiring, as they can identify potential loose connection problems leading to flashing LED lights and resolve any potentially hazardous issues.


LeonLite Well Lights


2. The LED is Non-dimmable

Not every LED is designed to be dimmable.

A prevalent cause of dimmable lights flickering and LED bulbs flashing when dimmed is that the LED is not actually dimmable.

Attempting to dim an LED that hasn't been designed for dimming will result in flickering, which is also a typical reason for buzzing LED lights.

Hence, LED light bulb flickering usually occurs when trying to dim a non-dimmable bulb.






3. Utilizing Non-dimmable LED Bulbs

Keep in mind that manufacturers offer the option to create a dimmable LED lighting circuit or pay slightly less for non-dimmable products.

Make sure to look for 'dimmable' on the packaging or in the specifications for light bulbs compatible with a dimmer to avoid issues like LED bulb strobing.

4. Defective Dimmable LED Bulbs

In case a single light bulb or fixture is flashing, try swapping it with a known functional one before further investigation to determine if the issue is a defective product.

If all the bulbs are flashing simultaneously, it's improbable that they are all faulty at once.

5. Incompatible Dimmer Switch for LED Lights

Even if an LED is dimmable, it may not function properly with every dimming system.

Dimmable lights can flicker if the dimmer switch has an unsuitable dimmer module. There are specific dimmer switches designed for LED lights, so ensure you purchase new and compatible controls when transitioning to LED lighting.

Using outdated dimmer switches with modern LED lamps may also result in incompatibility issues.

Preventing Dimmable LED Flickering

Dimming lights can be complex, and there are numerous reasons why dimmed LED lights might flicker. Based on our experience, here are some more detailed solutions.

6. Employ Dimmable Power Supplies

LED light sources typically use a transformer power supply called a driver, which can be designed as dimmable or non-dimmable. Drivers can be either internal within a product or external in the lighting circuit.

Using a non-dimmable driver with a dimmer will result in flickering LED lights.

7. Utilize PWM LED Power Supplies

Pulse width modulation (PWM) is a technique that allows LEDs to be dimmed by quickly switching them on and off at a rate too fast for the human eye to perceive. PWM provides smooth dimming; however, if not implemented correctly, it can expose dimmable LED flickering and flashing LED lights.

Verify whether you are using a PWM power supply if your dimmer switch employs adaptive dimming.

8. Assess Compatibility Between the Light and the Controls

LED lights may flicker when dimmed using an incompatible control.

It's essential to understand the relationship between the dimmer and light to prevent LED dimmer flickering.

Another suggestion to determine why your dimmable light flickers is to check if your light bulb or lighting circuit is a "leading-edge" or "trailing-edge" type and ensure its compatibility with the dimmer switch itself.

We delve deeper into the concept of dimming, explaining the methods you need to be familiar with and why certain LED lights flicker on dimmer switches.

9. Opt for an LED-Compatible Dimmer Switch

Flashing may also occur due to using an incompatible or unreliable dimmer switch.

Appropriate dimmer switches for LED bulbs have an 'RC' label on them.

LED lights can flicker on dimmer switches that are not sensitive enough to manage low power loading in the lighting circuit, so invest in a dimmer switch specifically designed for LEDs.

The best LED dimmer switches utilize a microprocessor to stabilize the current, which in turn prevents flickering and flashing in dimmable bulbs.

10. Is the Dimmer Switch in Programming Mode?

LED bulbs may flicker on contemporary dimmer switches left in programming mode.

Manufacturers enable you to identify which lights are on a specific circuit by providing a group flash, indicating it's in listening mode and awaiting instructions. If left in that mode, pulsing LED light replaces constant light.

Some dimmer models can be accidentally triggered by rapidly pressing a button or turning a rotary knob, either due to leaning on it or children playing with the switches!

Verify the switch is in the correct mode by following the manufacturer's guidelines.

11. Are You Dimming an Incompatible LED Type?

The reason behind LED light flickering may lie in the type of LED you're using. Your dimmable LED may be flashing because you might be trying to dim an incompatible LED light source with your chosen dimmer switch.

LED lights utilize one of these three types of power:

  • Constant Current
  • Constant Voltage
  • Direct Power

The right equipment setup is required to avoid flickering. For instance, an LED strip needs the appropriate constant voltage driver (power supply) coupled with a suitable dimmer module. Incorrect equipment combinations can result in flashing.

We explore how to dim LED strip lights for seamless LED dimming.

12. Have You Surpassed the Maximum LED Capacity?

LED light flickering may occur when there are too many LED bulbs or products on the circuit.

Dimmer switches have a load range, and attempting to use more LEDs than the design parameters allow can cause the switch to overload, resulting in flickering and flashing.

The dimmer switch's minimum and maximum power is always indicated on the packaging or at the back of the fixture itself.

To resolve this issue, simply remove some LED lamps from the circuit or install a new dimmer switch capable of handling the increased load.

13. Was the Dimmer Switch De-rated During Selection?

To handle the load and prevent flickering LED lights or failure to illuminate, you may need more than one dimmer switch or need to de-rate your current dimmer switch's loading capacity. This may involve leaving up to 70% unused to avoid complications. Although the circuit may not be overloaded beyond the recommendations, it might not start correctly or may exhibit visible flashing without enough spare capacity.

14. Is the LED Driver Undersized?

Dimmable LED drivers come in various capacities and must always be larger than the lighting circuit's load. It is recommended that the total wattage of all LED lights should not exceed 80% of the driver's wattage to ensure a longer product lifespan.

For instance, if you are using four 4W MR16 LED bulbs, you would require a 20W driver.

15. Are You Fulfilling the Minimum Load Requirement?

If the pulsing LED lights continue to flash, it's possible that your specific brand or model of dimmer switch requires a minimum load to be met.

Verify whether your switch is designed specifically for LEDs and can accommodate very low wattages. The Varilight V-Pro range, for instance, has no minimum load requirement, allowing it to dim a single low-wattage GU10 LED or LED downlight.

16. Dimmer Light Flickering at Low Levels

Traditional dimmer switches designed for incandescent and halogen light sources perform well with a minimum load of around 40 watts. LED bulbs may flicker on these switches if their total load is too low, particularly when dimmed below 50%.

A potential solution is to use a resistive (or dummy) load to increase the circuit's load, resolving the issue.

17. Consider Wireless Dimming

Another option is to utilize wireless lighting controls, where all lights are connected on a programmable network using low-frequency radio waves or Bluetooth mesh, such as Casambi or Philips Hue systems.

A professionally implemented solution often resolves the problem, provided the installation is supervised by the manufacturer or a consultant.

18. Invest in High-Quality Products

What is the quality of your dimmer switch and LED lights?

Generally, higher-quality dimmer switches and LED lights are less likely to cause problems. Reputable brands maintain their reputation through rigorous testing and post-sale support, so it's wise to invest in reliable products.

19. Dimmer Switch Overheating

Overheating electronic devices can cause them to operate beyond their tested ambient temperature range, potentially leading to erratic behavior such as intermittent LED flashing and strobing.

Ensure that the dimmer switch isn't overheating due to excessive wattage from dimming or proximity to other electronic devices near the switch plate.


Numerous factors can contribute to LED lights flickering and dimmable LED lights flashing. However, there are just as many solutions available to address flickering LED lights. By comprehending the underlying causes and implementing appropriate solutions, you should be able to resolve the issue efficiently and effectively.

Deck Lighting - Leonlite


Find Your Glow
Path Lighting - Leonlite


Find Your Glow
Wall Washing - Leonlite


Find Your Glow




Trouble Shooting

Outdoor lighting

Dimmable LED


Dimmer Switch

LED Driver

You May Also Like