Month: May 2014

Timer Switch for LEDS, Timer Light CFLs

Why does a timer switch not work with LED or low energy light bulbs.


Timer switch, LEDS, flashing bulbs

Timer switches use the lighting circuit to operate correctly.   The bulb acts as a resistor in the circuit for current to run back to the switch.  The timer runs a small current through the lights to operate. This is unnoticeable with regular lights.

However this  small current is enough to dimly light the LEDs or causing CFLs to flicker with the timer switch.

The timer switches therefore typically require a minimum load in order to operate.  this is usually 40w or more.

This also has the additional issue of the fuse in the timer switch blowing each time the light bulb blows requiring you to turn off the mains before replacing the fuse.

So How can you use a timer switch with your energy saving bulbs?Timer energy saving bulbs flicker

So what can you do?  there are a number of options available,

  • Get a large resistor.

Some timer switch manufacturers offer a larger external resistor which can be fitted between the bulb and the switch allowing them to operate bulbs of 20W.  these will not fit behind the switch and need to be wired into the ceiling.

  • Use old bulbs or more bulbs.

With CFLs you could try increasing the number of bulbs so if you have 3 bulbs of 15w you can meet the minimum load requirements of the timer switch.

but this still does not allow the timer switch to operated LEDs.

Get a timer which works with Energy saving bulbs, LED’s or CFL

Get a of timer which does not suffer from these issues as it mechanically operates the light switch and so can be used with any LED or CFL type bulb.

It operates the existing light switch.  This has the advantage that it does not matter what type of light bulb or LED you use you will not have any issues. In addition it does not require any wiring as it is a retro fit solution fitting over the existing switch.


timer switch cfl

timer switch cfl