Automatic light switch timers are wired into the mains lighting circuit.  However many of the homes in the UK do not have a neutral wire available at the switch.  So how do you connect them.

Can you put a timer on a light switch?

First of all you need to know what type of wiring you have at the switch.

If your switch only has 2 wires and an earth wire – this is a switched live arrangement and there is no neutral wire available.

Many electrical timers require a neutral so that the switch can be powered without sending power to the load.  If you do not have a neutral at the switch box it means that the power source (line) does not come into that box and you are just switching the hot from another source.

A traditional switch only switches the live so it does not need the neutral.   If there is no neutral then unfortunately, youneed to keep reading.

Wiring with no neutral

timer switch wiring

wiring a timer switch neutral wire

The neutral wire is use to provide power to the light switch timer for the clock.  this does require that you have three wires at the junction box (plus an earth) .  If you only have two wires at the switch you have a switched live type circuit.  You will need to get a neutral wire at the switch in order to correctly wire and power the device.

Most homes in the UK don’t have a neutral wire and so timer switch become quite difficult to install. However adding a neutral wire is not that easy.  An electrician should be able to add a neutral wire for you but this often requires cutting into the wall to get the wire to the switch you require it for.

How do you install your timer switch with no neutral wire?

The simplest way is to purchase a timer that does not need a neutral wire to operate.  This way you will not need to make any changes to the switch, and the timer will work with no neutral wire.

The mydome timer switch is not connected to your home electricity supply and does not rely on the neutral wore as a power source.  The timer uses two AA batteries to power the timer and mechanically switch the lights on and off.  This has the advantage that it can be used on the existing switch on your wall and requires replacing the existing switch.

It is Installed fitting the timer over an existing wall light – a small control wheel then turns the lights on and off by means of a control wheel on the rear of the unit to operate the switch manually.  The timer light switch can be used on single, double or triple switches and even allows the user to select which of the switches is operated via the timer.

Timer switch no nuetral required

Timer switch no neutral

5 comments on “Wiring a Timer switch No Neutral Wire

  1. Kevin Kwasnicki on

    Hey, I need a 5min to 60min timer in bathroom and have no neutral wire. It worked great till I putt in led bulbs, it blew the breaker and burnt the switch. And other timers that work with no neutral wire?
    Thanks Kevin

  2. Richard Badoian on

    Picture this…wall plug, indoor timer plugged into the wall and the light plugged into the electric timer. OK; now I need some kind of a timer that I can install into the electric box with only 3 wires(no neutral or 4th wire) to turn my outside light on at night & off in the morning.
    There has got to be such an item manufactured by someone. Is there anyone that knows where I can purchase one?

    • Tariq on

      Use GE Timer Switch model 15313. I did use this and my outside lights working itself on off with the timer i set up. Hope it will help. This Timer Switch work with three wires. Thirs one is green as connecting to earth wire. Good Luck

  3. Powerline Protection on

    Thank you very much for sharing on light switch timer wiring, it’s difficult for me to get such kind of information most of the time always… I really hope I can work on your tips and it works for me too, I am happy to come across your article.


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