In 95% of cases, you can swap a halogen bulb for an LED one, without any issues.

Rarely though, there can be an issue with flashing / flickering / random switching with the bulb.


1. Wire wound transformers - the old, heavy transformers, common for downlights 10yrs or older. These cannot be used with LEDs. A collapsing magnetic field sends a power surge through the LED, damaging it. Secondly, under a small load, the voltage output of them can be over 16v. If you ignore this advice, and return the bulb, we will be able to determine that the voltage regulator has been damaged

2. Electronic transformers with a min load - newer transformers are lighter and smaller. Most are compatible, however some have a minimum load requirement, and LEDs being efficient, don't meet it. So the transformer becomes confused: "do you want me to work or not?" it asks. It may flicker, flash or do some other bizzare things. This is NOT a faulty bulb you need to look at the transformer.

Usually the transformer will state on it's cover something like "20-60 VA". A 'VA' is basically a watt. Therefore, if putting in a 4w bulb, and the transformer states a min of 20, you may get a problem. Having said that, most transformers were not designed for 4w, and since a 20w halogen was the smallest thing they could test with, that may be how they determined the rating. Which means that often you can get away with it.

There are several solutions:

1. Upgrade from a 4w bulb to a 6w. Often this is all it takes

2. Wire multiple bulbs to one transformer

3. Change the transformer to another type (this often works, but is not guaranteed)

4. Install a LED driver such as this one

5. Convert from 12v (MR16) to 230v (GU10) type (requires GU10 lamp holder, $8 ea)

Some electricians have reported that they have installed large numbers of bulbs in a home, and most halogen transformers they purchased seperately from a wholesaler worked fine. Others however, despite being identical, had sufficiently different electrical tolerances to give different results. Perhaps they were a different batch. 'Possum' and 'Redback' have been found to be 90% successful, however 'Orbit' seems to be 100% thus far.

3. Dimmers - even if you have dimmable LED bulbs, dimming may cause weird behavior with an LED bulb and may damage it. Few dimmer switches are designed for LED. Very few LED MR16 bulbs can dim since very few electronic transformers use PWM dimming method. One solution is a dimmer like this that works on the 12v side. A 230v to 12v dimmable transformer like this can also be used on the 230v side.