Led lights are flickering - Help please

please specify the type of the dimmer first.
Some of the two wire dimmers (non-mechanical) would not work even if LED are dimable, this is because two wire switches wit digital or electrical control need some minimum flow of energy.
you have two options. Either use mechanical dimmer or 4 wire one.
second option is if you have bout low woltage dimable LED's
If LEDs are not 240 (GU10)s then you need dimmable transformer and Has to be Dimmable LED transformer, not spotlight transformer or standard LED transformer(driver)

 

If yours is standard then yes (tigar), you will need to replace it.
Personally I try to stick to GU10, but at this stage it is too late
GU10 are easier to deal with as you do not need to be changing transformer

 

GU 10s all the time As Zlodje states some dimmers need a minimum current flow and obviously suitable transformers required

 

That is normal especially if you are converting from normal MR16 as standard spotlights eat so much power that it would be too much for transformers to run more of them.
You cannot use MR16 transformers for LED, but you can power more LEDs' from one LED driver (transformer) in either occasion you will have to remove standard MR16 transformers.

As far as I know the Diameter of MR16 and GU10 (check this claim before taking action on it as I have newer checked it) in which case all you have to do is to swap the plug from MR16 for standard GU10 (these you can get from any proper electric shop) skipping the transformer completely (GU10) does not need it.

If on the other side you already have MR16 bulbs, you want to put the Dimable LED driver before them skipping the MR16 transformers

 

We have not used simple transformers for years. The step down devices contain transformers but also contain electronics and in the main the transformer is high frequency and with tungsten we use the AC output and with LED in the main a smooth DC output most of the DC outlet voltage droppers seem to be called drivers however they are not really drivers as a driver controls current not voltage. In the main the LED unit (bulb) consists of LED's with some sort of voltage reducer often switch mode in which case the supply must be altered in a way to cause the switch mode unit in the bulb to stop doing it's job in controlling the LED to give maximum output. To get the power supply to do this the dimmer switch also has to tell the power supply to stop doing it's job of giving a regulated output. So although it can be done the dimmer, power supply, and lamp unit all have to match so you would need to buy all three together and clearly same manufacturer for them to be sure to work. Even then it requires a balanced feeder to be really sure, which in practical terms means you may need to trim length of connecting wires to stop the high frequency from causing a poor standing wave ratio.

After saying all that the LED when dimmed does not change colour like tungsten so does not create the ambience of the tungsten lamp so may as well just control how many are lit rather than how bright they are. Especially since the whole idea of LED's is to save power and to control the LED in an efficient manor we use switch mode control but to allow dimming easier to use a simple resistor so it's likely dimmable LED units are not as efficient as non dimmable type although I have never reverse engineered one to find out.

Once the mark/space ration of a switch mode regulator reaches the point where it can't increase the mark any more it will dim the LED however this likely means as you reduce from 12 volt to approximately 9 volt there will be no dimming but then from 9 to 8 volt it could well go from full to zero output this means often the dimming switches are not linear.

Why anyone would want to dim quartz lamps I don't know either these are specially designed to keep the envelope at a critical temperature to prevent tungsten being deposited on the envelope to ensure this critical temperature is maintained giving long bulb life we use a regulated high frequency extra low voltage power supply to then use any device to stop it doing it's job is crazy. Dim standard tungsten yes but not quartz. Lecture halls want to be able to balance the light bright enough to see speaker but dim enough to see any projected presentation so they have some very clever and expensive equipment to allow dimming of florescent lamps but this is hardly required in the home.

As I have said dimming without also changing the colour temperature does not give the ambience required. What we really need is a special light fitting which is controlled by TV remote so when the TV is on half the lights are switched off or even an app for a phone. But the days of the cheap dimmer are gone. Yes one can be lucky and find a combination that works but it's more by luck than design.

 

That sounds like a very sensible plan Asif and I done a very similar job quite recently.

 

I have 3 "candelabra" (each has 3x60w bulbs on a ceiling drop) each has a dimmer switch. Changed to 5w LEDs and they all flickered on full power. New dimmers cost £20. I read the info - a 400w dimmer can't work with just 15w. So I put back one 60w filament in each candelabra. They all work perfectly, I have 6 filament bulbs and 3 LEDs spare. I've saved 100w on each candelabra. By the time ive used all the spare filament bulbs, good LED dimmer switches will be a sensible price. Hope this is helpfull.

 

Might of helped 2 year ago not so much now

 

So you have 2 leds and 1 incandescent in the candelabra fitting, must look real good!.
Do the right thing, either go fully led and purchase the correct dimmer, or stay with incandescent.