Flickering LED Lights: A Complete Troubleshooting Guide

LEDs have come to the forefront of the market in recent years; investing in LEDs not only saves you a lot of money, but dramatically reduces the hassle of relamping and replacing units. With fluorescents gradually being replaced by LEDs, you may have thought the days of flickering lights were completely over. Though T8 LEDs are usually free of issues and flickering happens less often than with fluorescents, sometimes LEDs can blink, flicker, or even fail to turn on altogether. Generally, finding a solution to these issues is a relatively simple process. Read on for a few simple steps you should carry out to establish the root of the problem. We recommend that all the below steps be taken by qualified, registered electricians.

Step One – Identify Your Current Setup

The first step to identifying the problem is to evaluate your current setup. Check your lamps, wires, ballast/driver, and tombstones for bad connections or loose wires. A common reason for flickering T8 LEDs is a loose connection within the circuit. Addressing a power-connection issue or loose wire to the driver circuit will often easily resolve the flickering or no-power issue. Ensure the lamp is screwed correctly in place and the connection point hasn’t become loose over its lifetime.

• Check for loose wires.
• Tighten and securely screw lamp correctly in place.
• Ensure the connection point hasn’t become loose.
• If the wiring is loose at the connection point, disconnect power to the circuit and secure wiring as needed.

Step Two – Narrow Down Other Potential Points of Failure

If your wiring and connections are working, the issue may be resolved by checking for incompatible switches. Many new T8 LED lamps are incompatible with older dimmers and switches. There are a number of other potential points of failure resulting in the flickering or power issues with your LED lamps, including:

• Incompatible switches
• Driver components
• Relaxation oscillator
• Incorrect power/surge wattage
• Changing voltage levels

Regarding Incompatible Switches

With the exponential advancement of LED technology, a lot of modern LEDs are not compatible with older switches we have known and used for years. Dimming switches cause the most issues because many of them are incompatible with modern LED technology. To test if your switches are causing the flickering in your LED bulbs, test your switches by replacing your bulb with a traditional incandescent bulb.

Most dimmers work via phase cutting,  meaning voltage is reduced. While this is useful in many situations, an LED circuit has more difficulty with this process, resulting in an amplified flicker or lack of power on startup. If your application requires dimming, there are LED-specific dimming switches available. LEDs are almost always a worthwhile investment, so ensuring your current solution works in conjunction with this new technology is important. Evaluate your application and make the necessary changes required to ensure your LEDs run how they should.

Driver Components

In many cases, the flickering of a T8 LED can be related to the driver components within the lamp. By using a controlled output current to reduce the risk in altering frequency, T8 LED lamps are less likely to flicker. Constant-current drivers help avoid any peaks in the current wave, eliminating any flickering.

Relaxation Oscillator and Electronic Series Resistance

Cheap lamp components—such as a capacitors (they store energy), which are heat sensitive and often come with low rated lives—can affect the output of your lamp. Capacitors control the current supplied to the LED through a driver module. An equivalent series resistance (ESR) is a change in a lamp’s characteristics and performance caused by cheaper components, uncontrolled temperature, and frequency interruptions. Another electrical effect that can cause power issues and flickering of an LED lamp is known as a relaxation oscillator. A relaxation oscillator causes the capacitors inside an LED lamp to flip between their on and off cycles; a charging cycle when the lamp is powered off means the lamp should remain turned off but the relaxation oscillator effect causes temporary (i.e., nanoseconds-long) illumination, which the average person sees as a flicker.

Incorrect Power and Surge Wattage

When a lamp is first installed, it requires more power than if it had been running on a consistent basis for some time. This extra power can put a strain on the LED lamps and cause them to flicker, typically as a result of a drop or surge in power. To prevent this issue, it is recommended to move larger-load items to a high-volt circuit. This eliminates the pressure on the entire voltage load, thus eliminating the risk of flickering.

Changing Voltage Levels

Voltage levels change through the wiring of an application. Voltage flows through each wire, each of which use a specific voltage level. A change in voltage level can be caused by multiple appliances being used at one time, causing peaks and dips in your voltage levels, resulting in a flickering lamp. This is a common problem in many households due to the amount of appliances using a heavy power load. Check the current running to your home/office/space to ensure it provides adequate voltage levels to run everything you need, when you need them.

Step Three – Address the Malfunctioning Component

When you have tested all components and narrowed it down to the malfunctioned component, speak to you manufacturer and explain the tests you’ve carried out. If your lamp is in warranty, your manufacturer should replace it. If the lamp is out of warranty, your manufacturer can help you find a replacement piece. It is advised to always have a qualified electrician switch out the components to assure safety remains a top priority.