When you’re choosing a new switch or dimmer, you’ll often see terms like 1-way, 2-way, or even 3-way / multi-way control. These might sound confusing at first—but they simply describe how many switches control a single light or lighting circuit. Let’s break it down.
What is a 1-Way Switch or Dimmer?
A 1-way control means that one switch (or dimmer) controls one light or group of lights (in the same circuit).
It's the most common and simplest setup—perfect for small rooms, bedrooms, or anywhere you only need one control point.
Example:
A dimmer or switch by the bedside that controls a single ceiling light.
Key feature:
Power flows in a single direction—from the live wire to the light fitting.
Only one control point.
What is a 2-Way Switch or Dimmer?
A 2-way control means that two switches control the same light circuit—for example, one switch at the top of the stairs and another at the bottom.
Each switch can turn the light on or off independently.
Example:
Hallways, staircases, or long corridors.
You can switch the light on when you enter, and turn it off when you leave—from either end.
With Dimmers:
In a 2-way connection, you can only use one dimmer, and the other must be a standard 2-way on/off switch, such as a 2-way rocker switch or a 2-way toggle switch.
If you wish to install two dimmers in a 2-way system, please use our multi-way dimmers. With these, you can install up to five dimmers in the same circuit (allowing control of the same light or group of lights from five locations, with full dimming functionality at every dimmer).
What is a 3-Way or Multi-Way Control?
3-way control is also known as multi-way control. Generally speaking, when there are more than two switches or dimmers on the same circuit, the system is collectively referred to as multi-way control (or 3-way control).
It is important to note that if standard on/off switches are used in the system, all other control points must also be on/off switches; they cannot be mixed with dimmers.
Similarly, if dimmers are used in the system, all other control points must also be dimmers; they cannot be mixed with on/off switches.
A traditional multi-way switch system requires the use of two 2-way switches and one or more intermediate switches, as illustrated in the diagram below.
This wiring diagram is based on Repenic switches (click here to check) and is intended solely as an illustrative guide to explain the multi-way system in conjunction with this article. It must not be used as a wiring diagram for any other brand.
A multi-way dimmer system, however, must use specialised multi-way dimmers (click here to check); they cannot be mixed with standard 2-way dimmers.
