Following Up on the LED Dimming Dilemma
If you followed our popular article on a specific Varilight LED light switch issue (which generated a fantastic amount of local interest!), you know that dimmable LED lighting remains one of the trickiest areas for homeowners and electricians alike. The promise of energy-saving, dimmable lights is fantastic, but the reality is often a headache of buzzing, flickering, and frustrating incompatibility.
As experienced electricians working across South London, we are constantly dealing with these setups. With 2026 right around the corner, this article is an important follow-up and an update on the current state of play—especially concerning specialised fittings like recessed downlights and the latest solutions from manufacturers like Varilight. We’re here to explain why issues persist, and how we fix them in late 2025.
The Core Problem: The Blame Game Between Manufacturers
The main reason for these issues is a simple lack of communication in the supply chain:
“Basically, you have manufacturers that make light switches and manufacturers that make LED bulbs. They can then blame each other for the lights not dimming properly.”
It’s a classic case of components not playing nicely together. While the switches are getting better—with many moving to multi-mode compatibility for both older Leading Edge and modern Trailing Edge systems—the underlying technology in the bulbs is often the sticking point. The switch might be compatible, but if the internal electronic driver of the LED is poor quality or incompatible with the specific switch model, problems are guaranteed.
Focusing on Recessed Downlights
When we get a call out in South London, the issue often involves modern, sleek recessed downlights. These lights are slightly more specialised than standard pendant bulbs.
- Low Wattage, High Sensitivity: Downlights typically run on very low wattage, making them incredibly sensitive to the minimum load required by the dimmer switch.
- Driver Incompatibility: Each downlight has a small electrical driver built in. If the collective minimum load of these drivers doesn’t meet the dimmer’s minimum threshold, the circuit will be unstable.
Even if you install a new, dedicated LED dimmer, if the combination of the dimmer and the downlight is wrong, you will get poor performance.
The Unexpected Symptoms: It’s More Than Just Flickering
Flickering is the most common sign of incompatibility, but in our experience across areas like Clapham, Balham, and Battersea, we are seeing more extreme symptoms:
- They Don’t Dim (or Don’t Work At All): The lights might stay stuck at full brightness or simply fail to switch on because the low-level signal from the dimmer is not properly recognised.
- The Lights Turn on By Themselves: This is perhaps the most alarming symptom. Known as ‘ghosting’ or ‘glowing,’ this happens when the dimmer, even when supposedly ‘off,’ still allows a tiny residual electrical current to pass through. This minimal current is enough to trigger the extremely sensitive LED chip, causing the lights to faintly glow or, in some cases, flicker or come on by themselves.
The Good News: Varilight’s Latest Moves for 2026
The industry is constantly playing catch-up, and we are seeing positive movements.
Manufacturers like Varilight seem to be discontinuing some of the older, less reliable switches and focusing on newer, sophisticated ranges like the V-Pro series. Our experience suggests these newer models offer better compatibility and more user-adjustable settings to fine-tune the dimmer’s performance to the specific load. While it’s getting there, compatibility issues still arise, which is where a professional electrician is indispensable.
We are staying on top of these changes. In fact, we are scheduled to fit some of these newer Varilight switches next week for a client in the Battersea area (SW11), a job that came directly from the visibility of our previous blog article. This hands-on experience ensures we always recommend and install the most current and compatible products for your South London home.
Local Expertise in Battersea and South London
If you are experiencing any of these strange dimming issues—whether it’s buzzing, flickering, or your lights turning on without your permission—don’t throw out your entire lighting system.
Contact South London Electricians today. We have the up-to-date technical knowledge and hands-on experience with the latest switches, drivers, and regulations (heading into 2026) to correctly diagnose the issue, reprogram or replace the right component, and ensure your LED lighting delivers the energy efficiency and performance you paid for.