How to wire a 2-gang switch plate

Helpful video reference. We use GSH Electrical's "2 Gang Switch Connections Explained - Taking the Feed to the Switch" as the video reference here. GSH Electrical is a UK electrical training channel covering City and Guilds and EAL qualifications. The video demonstrates the 2-plate method clearly, stepping through each terminal on a real switch plate with the cables labelled, which makes it much easier to follow than a diagram alone.

1. Understand which wiring method you have

Two wiring methods are common in UK domestic lighting circuits.

• Feed to switch (2-plate method): the supply cable arrives at the switch box. The switch box contains the line, neutral and CPC. Switch drop cables run from here to each light fitting. This is the method this guide covers and the one shown in the video.
• Feed to light (loop-in / 3-plate method): the supply arrives at the light fitting or ceiling rose. Only a switch drop cable runs between the switch and the light. If this is what you have, the wiring at the switch plate is simpler but the back box will look different - typically just one cable with two cores and an earth.

If you are not sure which method you have, a helpful indicator is whether you can see a blue (neutral) conductor in the switch back box that is not re-sleeved brown. If there is a bare neutral connected to a Wago or terminal block alongside other neutrals, you likely have the feed-to-switch arrangement.

2. Isolate at the consumer unit

Switch off the MCB or RCBO for the lighting circuit. If the two gangs serve different circuits on different MCBs, switch off both. Lock out or flag the breaker if anyone else is in the building.

Return to the switch and test with your two-pole voltage tester on every conductor you can see. No live reading anywhere? Good. Leave the tester to hand throughout - you will use it again before reconnecting.

3. Photograph before you disconnect anything

Unscrew the two faceplate screws, ease the plate away from the back box and look at each terminal. Take a clear, well-lit photo from directly in front of the plate so every terminal and conductor is visible. If the existing wiring is tangled or the photo is blurry, take another one. This photo is what you will refer to if anything goes wrong during reassembly.

4. Identify the terminals

A standard 2-gang 1-way switch plate has six terminals in two groups of three. From left to right on each gang (the exact layout varies by manufacturer, so check the back of your plate):

• COM (Common): the incoming line conductor. Always connected.
• L1: the switched live going out to the light fitting. Connected for 1-way and 2-way switching.
• L2: only used for 2-way switching (stairs, landings). Leave empty for a 1-way circuit.

For a 2-gang 2-way switch plate, there are six terminals too (COM, L1, L2 per gang). The principle is identical - COM takes the incoming live and L1 takes the switched live; L2 is only needed if this location is the second switch in a 2-way circuit.

5. Connect Gang 1

With the feed-to-switch method, the supply line (brown) conductor connects to COM on Gang 1. The switched live going to Light 1 (the brown core of the switch drop cable to that fitting) connects to L1 on Gang 1.

Tighten the terminals firmly - most modern plates use a push-in or screw clamp. A loose terminal will cause arcing over time. Tug each conductor gently after tightening to confirm it is seated.

6. Connect Gang 2

If both gangs share a single supply cable in the box, the line needs linking from COM on Gang 1 to COM on Gang 2. This link is sometimes a short piece of brown 1.0 mm² conductor or a proprietary link bar supplied with the switch. If the two circuits enter on separate supply cables (for example, two independent lighting circuits), each COM connects directly to its own supply line - no link required.

Connect the switched live for Light 2 (the brown core of the second switch drop) to L1 on Gang 2.

7. Connect neutrals and CPCs

In the feed-to-switch arrangement, neutral conductors do not pass through the switch terminals. All neutral cores - from the supply cable and from each switch drop - join together in lever connectors (Wago 221 or similar) inside or alongside the back box. Check that each connector is firmly seated and that no copper is visible outside the connector body.

Sleeve any bare circuit protective conductors in green-yellow sleeving. Connect all CPCs together, then run an earth tail to the earth terminal on the switch plate. If the back box is metal, run a second tail to the earth terminal on the box itself.

8. Refit and test each gang independently

Fold the conductors carefully back into the back box - do not trap any insulation under the edge of the plate. Tighten the faceplate screws evenly so the plate sits flush. Restore power at the consumer unit.

Test Gang 1 by switching it on and off - only Light 1 should respond. Then test Gang 2 - only Light 2 should respond. If either light fails to operate, or if the wrong light comes on, switch off at the consumer unit and re-check the switch drop connections against your photo.

When to call us

A straightforward like-for-like switch swap in Sandwich is usually a small local job at the £10 per 10-minute rate. If the back box is metal, the existing wiring is old, or you are adding a new 2-gang plate where there was only a 1-gang before, it is worth a quick call first so we can tell you what to expect.