Smart lighting comes in three forms: bulbs with intelligence built in, switches that replace the wall plate, and modules that sit behind the existing switch or at the fitting. Each has a different failure mode and a different effect on how other people in the house use the lights. Understanding the differences before you buy prevents most of the frustration.
Smart bulbs
Smart bulbs are the easiest starting point. They screw or bayonet into an existing fitting and need no wiring work. The catch is that they must remain powered to be controllable, so if anyone flicks the wall switch off, the bulb becomes unresponsive until it is switched back on.
They suit table lamps, feature fittings and rooms where the wall switch is rarely used. They suit downlighter arrays badly, because ten smart bulbs cost far more than one smart switch and you have ten devices to update instead of one.
Smart switches
A smart switch replaces the wall plate and controls the circuit rather than the lamp. Everyone in the house uses the wall switch normally, and the lights are also controllable remotely. This is usually the right choice for ceiling lighting.
The requirement is a neutral in the back box, which older UK lighting wiring often lacks. Some switches work without a neutral by drawing a small current through the lamp, which can cause glow or flicker with low wattage LED fittings.
Smart modules
A module is a small relay or dimmer hidden in the ceiling rose or behind the switch, keeping the existing switch plate in place. This is the discreet option and works well in period properties where you do not want to change the look of the switches.
Space is the constraint. A shallow metal back box may not accept a module, and a crowded ceiling rose can be a tight fit. An electrician can usually tell from a quick look whether a module will fit.
Why LEDs flicker and buzz on dimmers
Flicker at low brightness, a buzz from the fitting, or lamps that will not switch off fully are almost always a compatibility mismatch between the dimmer and the LED driver. LED loads are small and electrically very different from the filament lamps that older dimmers were designed for.
The fix is a trailing edge dimmer rated for LED loads, set to the correct minimum brightness trim, and lamps from a single manufacturer and batch. Mixing three brands of LED on one dimmer circuit is a reliable way to produce flicker.
- Use a trailing edge dimmer designed for LED loads
- Check the dimmer's minimum load and stay above it
- Match all lamps on one circuit to the same model
- Set the minimum brightness trim during commissioning
Two way and multi way switching
Rooms with two switches, such as hallways and stairs, need smart products designed for multi way operation. With smart switches, one becomes the controlling device and the other is configured as a secondary. With modules, the existing two way wiring is often retained and the module simply sits at the fitting.
This is worth mentioning to your electrician up front, because retrofitting multi way smart control is meaningfully harder than single switch positions.
Local control matters
Systems that process commands locally continue working when broadband is down. Cloud only systems do not, which means an internet outage can leave you unable to dim your kitchen lights. Wall switches should always still work mechanically as a fallback, whatever the platform.
Choosing sensibly
For most homes, smart switches on the main ceiling circuits, smart bulbs in a few lamps, and nothing else is the arrangement people actually keep using after the novelty passes. Start there, live with it for a month, and expand only where you find yourself wanting more control.
Commissioning matters as much as the product
A smart dimmer that has not been commissioned will usually misbehave. Setting the minimum brightness trim, selecting the correct dimming mode for the driver and confirming the load sits inside the dimmer's rated range are all part of the installation, not optional refinements. When we fit dimmers we run them from full to minimum and back, on every group, before leaving, because that is when flicker and drop out reveal themselves.
Common questions
- Why do my LEDs flicker on a dimmer?
- Almost always dimmer and driver incompatibility. A trailing edge LED rated dimmer with matched lamps usually resolves it.
- Can I use smart bulbs with a smart switch?
- It is generally a bad idea. The switch can cut power to the bulb and make it unresponsive.
- Do I need a hub?
- Some systems do, some work over wifi alone. Hub based systems are usually more reliable at scale.
- Can smart switches be fitted in old back boxes?
- Sometimes. Many need a deeper box and a neutral, both of which may require minor building work.
- What happens in a power cut?
- Everything is off. Most systems restore their previous state when power returns.
We fit smart switches, modules and LED compatible dimmers, and we test the dimming curve before we leave.
Related guides
- Getting LED Dimming RightMost LED dimming complaints are a compatibility problem, not a faulty lamp.
- Planning the Wiring for a Smart HomeThe cheapest time to future proof a house is while the walls are open. The second cheapest is never.
- Smart Lighting: Wired, Wireless and HybridThe most important smart lighting decision is where the intelligence lives.