LED downlighters

[Ifonlyiweretaller]

We wanted to change some our 'warm white' for 'cool white' as it is easier to read under a brighter light. I took one of the warm whites to an electrical wholesaler and he ordered me 30 in the cool white. They are not identical brand but in theory at least they are the same.

Having replaced two lines of them in the dining area, most of the new ones are flickering, and one just went out completely after being on for a while. Next time we turned the bank of 5 on, it was working again. One of them in the other line of 4 was flickering so badly we put the old warm white one back in and it's been fine, no more flickering.
I am totally confused by this. We have replaced like for like (same 12v 5w AC/DC MR16 ) so I dont understand why this is happening. We are paying over £10 incl. vat (and that's with our company discount!) for each bulb so its not as if we're gone for cheap and cheerful. The supplier has always been very good so we're really puzzled by this.
Transformers has been mentioned but I don't understand why they suddenly can't do the job they were put in for, just because we have changed some bulbs from warm to cool white. The warm white ones have been in for over 12 months (a total of 29 just in the kitchen/dining area) and we have never had a problem with them.
Sorry for the long post but I'm really frustrated - is there anyone here who can make any suggestions please?

If they are the exact same fittings and wattage, just check that they are in correctly and tight. If they are and are still flickering, return them as they are faulty.

I could have written this post. Experiencing exactly the same thing. In our kitchen/diner we have warm white leds in the dining area all work brilliantly and have done so for over a year. In the kitchen where we have only 8 units we have replaced some bulbs twice already and at the moment have one dead and two flickering. They even continue flickering when we switch them off! Watching with interest...you're not alone.

I had a bad batch, flickering straight away, tried a different make and fine. I have found my LEDS lasted nowhere near the claimed hours.

Is it a dimmer issue? If you have a dimmer switch, you have to have dimmable bulbs

We changed our fittings to mains voltage to avoid transformer issues. Ours was that turning lights on completely cut out our DAB signal. We now have "lap" from screwfix & would recommend

Thanks Teatificateman. It's my OH who fitted them (and by his own admission manual work is not his strongpoint!) but I have made him double check the fittings...
Katb - although it doesnt help you, am so relieved it's not just me! We have 156 bloody downlighters in our house (even 6 in the flipping utility room which is only small - talk about overkill!) so we need to get this issue solved!
Boulshired - personally we've found they are a massive improvement on the old lights. My OH notices as it was about the only bit of manual work he ever did, changing those pesky bulbs (or 'lamps' as they're known in the trade, which confuses me).
And Blownin - no, these particular ones aren't on dimmers. That's a whole other issue that I am i the process of sorting - we have finally found LEDs that will work to replace the existing crap ones (in the bedrooms/ living room etc) but I m not prepared to shell out for them yet as they are even more expensive (despite being a much smaller lamp size) until we get this first issue sorted.
Savagehk - sorry but I dont really understand your reply. Sounds way too technical for me! What i would say though is why should I have to faff about and spend even more money when I am literally just replacing like for like?
I appreciate all your replies...luckily the coll white light above my laptop is not flickering...

I agree, you shouldn't have to faff about. But when we had our issue the reading i did suggested if you have transformers and bulbs there's one more thing that can be incompatible, as different bulbs are made differently. Would using the same brand as the warm white but moving to cool white fix the issue? Have you replaced all bulbs at the same time, or at least all the ones from the same transformer?

Morning Savage! Thanks for further suggestions, I may try to get the same brand - it was a different wholesalers I bought that type from, but I imagine our new ones could get them too. It must be worth a try!
I replaced all the bulbs that work on each switch (one has 4, one has 5). But i have no idea how many transformers there are. How would I find that out?
I do appreciate your superior knowledge, I'm out of my depth as I'm sure you've realised, but really want to get my head around it all.

Not sure i have superior knowledge ;)

were the old ones LED?

they haven't been out very long.

Hi PigletJohn. Yes they were LEDs. I replaced them all (at great expense) over 12 months ago. My husband wanted some of them replacing with brighter white ones whicj is what we had started doing, hence the issue...