EZSMART Corp, ESA/ECRA #7012690 , North York , Ontario
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An LED bulb that glows faintly — or stays partially on — after the switch is off is a common issue in modern homes. It’s usually not a wiring fault. Here’s why it happens and how to fix it.
In older Canadian homes, some switches were wired in a “switch loop” configuration where the switch interrupts the neutral wire rather than the hot. When this is the case, there’s a small amount of current that can still flow through the LED’s internal driver even with the switch off, because the hot wire remains energized at the fixture. LEDs draw so little power that this residual current is enough to cause a faint glow. This is not a safety hazard, but it’s annoying and can shorten the driver’s life.
Many electronic dimmers and smart switches require a small amount of current to power their internal electronics, even in the off state. This “bleeding current” passes through the LED driver and causes a faint glow. Leakage current varies by dimmer model — Lutron and Legrand dimmers generally have lower leakage than cheaper alternatives. If the glow appeared after installing a smart switch or dimmer, the dimmer itself is almost certainly the cause.
Three approaches work depending on the cause. First, try a different LED bulb: some LED drivers are more sensitive to leakage current than others. A bulb rated explicitly as “dimmer compatible” or from the dimmer manufacturer’s tested list often resolves the glow. Second, install a Lutron LED+CFL dimmer accessory (the LUT-MLC, about $20) in the light box — it provides a minimum load that absorbs the leakage current. Third, replace the switch with a “neutral wire” smart switch model, which does not require leakage current to power its electronics — these are now the standard for new installs.
If the light stays on at full brightness, not just a faint glow, that’s a different issue — the switch may have failed in the closed position, or there’s a wiring fault. Turn off the breaker and inspect the switch. A switch that’s failed closed will not interrupt power when flipped, and the fixture will stay fully on regardless of switch position.
When we upgrade older homes to smart switches, we specifically look for the neutral wire at the switch box. Without a neutral, the smart switch has to draw leakage current through the bulb to power itself — and that leakage causes glow on many LEDs. Homes built after the late 1990s usually have a neutral at every switch location. Older homes often don’t. If you have no neutral at the switch box and want a smart switch without ghosting, the Lutron Caseta system works specifically without a neutral and has zero leakage current — it’s our standard recommendation for older Toronto homes.
LED ghosting or smart switch compatibility issues? Call us at 416-838-9006 or visit our contact page — we install and troubleshoot smart switches across the GTA.
Electrician Since 2008 Journeyman Electrician Designated Master Electrician at EZSMART Corp
