LED Dimmer Switches: Gangs and 2-Way Guide

Gangs and 2-way: what they mean

The number of gangs is how many separate lighting circuits the switch controls. A 1-gang dimmer dims one circuit; a 4-gang dimmer dims four from one plate. Choose the gang count to match the lights you want on individual control.

Two-way means the dimmer can be wired into a circuit where a light is switched from more than one place, for example both ends of a hallway or landing. In a two-way setup the dimmer usually sits at one position and a standard switch at the other.

Gangs	Dims	Typical room
1-gang	One circuit	Bedroom, single downlight loop
2-gang	Two circuits	Living room with two lighting zones
3 and 4-gang	Three or four circuits	Open-plan kitchen-diner, large rooms

LED compatibility

This is the question that trips most people up. To dim LEDs successfully you need two things: lamps that are marked dimmable, and a dimmer designed to handle them. The BG Nexus and Flatplate dimmers are rated for dimmable LED and CFL as well as traditional loads, and they include an adjustable minimum-level setting. That feature lets you raise the lowest brightness point so LEDs stay stable instead of flickering or dropping out at the bottom of the range.

Non-dimmable LED bulbs will not dim and may flicker or buzz on any dimmer, so always check the bulb packaging first. Where possible, use the same make and type of lamp across one circuit, as mixing bulbs is a common cause of uneven dimming.

Load and the 400W rating

These dimmers are rated up to 400W. LED lamps draw far less power than the halogen bulbs they replaced, so the wattage limit is rarely the issue. The bigger consideration is the minimum load and the number of lamps, because some dimmers behave poorly with only one or two low-wattage LEDs on the circuit. Add up the actual wattage of your lamps and follow BG's stated limits rather than simply counting bulbs.

Fitting notes

The BG push-type dimmers press on and off and rotate to set the level. They need a minimum mounting box depth of 25mm, and a 10mm spacer is available where extra wiring room is needed. Replacing a switch is straightforward, but it is mains work: isolate the lighting circuit at the consumer unit first, and if you are unsure use a qualified electrician.

Frequently asked questions

Are BG dimmer switches LED compatible?

Yes. The BG Nexus and Flatplate dimmers are suitable for dimmable LED and CFL lamps, and have an adjustable minimum-level feature to steady low-brightness dimming. The bulbs themselves must be marked dimmable.

What does 2-way mean on a dimmer?

It means the dimmer can be wired into a circuit controlled from two positions, such as both ends of a landing. The dimmer sits at one position and a switch at the other.

Why do my LEDs flicker on a dimmer?

Usually instability at low brightness, non-dimmable bulbs, or a mix of lamp types. Use dimmable lamps, keep them the same type, and use the dimmer's adjustable minimum-level setting to raise the lowest point.

How many LED bulbs can I run on a 400W dimmer?

LEDs draw far less than their old halogen equivalents, but dimmers have minimum and maximum loads. Add up the actual lamp wattage and follow BG's stated limits rather than counting bulbs alone.

What gang dimmer do I need?

One gang for each lighting circuit you want to dim independently: 1-gang for a single circuit, up to 4-gang for four.