Change halogen downlights to LED: globe swap or new fitting

In short. Cosmo Lighting Kensington stocks LED replacements for both common halogen downlight globes, GU10 and MR16. A GU10 halogen (240 volt, twist-lock) swaps straight for an LED GU10. An MR16 halogen (12 volt, two pins) runs from a transformer in the ceiling, and an old halogen transformer often will not run an LED steadily. A globe is yours to change; a new fitting, a wired-in transformer or a new dimmer is a licensed electrician's job.

Which halogen downlight do I have?

Switch the light off, let it cool and take the globe out. A GU10 has two short pins with flat feet and twists a quarter turn to release; it runs on 240 volts straight from the circuit. An MR16 has two thin pins and pulls straight down; it runs on 12 volts from a transformer above the ceiling. The base type is printed on the globe.

Can I swap a halogen globe for an LED globe myself?

Yes. The globe is the one part a householder may change. Match the base (GU10 or MR16), choose a dimmable globe if the room has a dimmer, and choose the colour: 3000K warm white looks closest to halogen. The steps are in how to change a downlight.

Why does my new LED MR16 flicker or not light?

Usually the transformer. Halogen transformers were made for globes of 35 to 50 watts; an LED MR16 draws a small fraction of that, often below what an old transformer needs to run steadily, so it flickers, buzzes or stays dark. The fix is an LED-compatible driver in place of the transformer. Where it is wired in, that is your electrician's job, and it is the moment to ask whether 240 volt GU10 or integrated LED downlights would be the simpler change. If the flicker shows only when dimmed, the dimmer is the cause: see LED downlight flickering.

When is a new LED downlight better than a new globe?

When the halogen fittings are old or discoloured, when the transformers would all need replacing anyway, or when insulation has been pulled back from hot halogens. An integrated LED downlight runs far cooler, and IC-rated models are made to sit in contact with insulation, so the insulation can go back over them. Measure the existing cut-out before choosing: 70mm and 90mm are common. Fitting new downlights is an electrician's job.

How much power does an LED save over a halogen?

A 50 watt halogen globe is commonly replaced by an LED globe of around 5 to 7 watts giving similar light, and the LED lasts many times longer. The wattage and the lumens (the light output) are both printed on the box, so compare lumens, not watts, when choosing.

Warm white or cool white?

For rooms that felt right under halogen, 3000K warm white. Halogen sits at about 2800K, so 4000K cool white will look noticeably whiter. The full comparison is in warm white vs cool white.

Where this fits at Cosmo

• LED downlights & ceiling lights at Cosmo
• Light globes at Cosmo
• How to change a downlight