I've replaced halogen ceiling fan bulbs with candelabra base LED retrofits meant for chandeliers.

You can find many different styles in the big box home centers. You'll probably want to look for the highest lumen number available. Make sure you're getting the color temperature you want: warm (2700k to 3000k), cool (4100k or so), or cold (5000k to 6500k).

Measure the fan's bulb area first to make sure you have enough clearance around the bulb. You should, since halogen lamps get HOT, so they usually need much more clearance than the LED retrofits. But if you can't find one locally that fits, you might try something like this (no endorsement intended, I have no experience with the brand).

DavidR,

I don't know whether you were referring to the problem I just discovered today.

My fan is made by a company called minkaAire. They
have a tech support office. Just called them (they were closed over the
weekend).

They claim that customers who have tried to use LED bulbs have had
problems because the receivers for the fans are programmed for halogen
bulbs.

They further explained that the fans they are now making are programmed to use LED bulbs.

I asked them whether there's anything I could buy to retrofit my fan so
that it takes LED. They said there's nothing out there at the moment.

Damn! It had never occurred to me that if I got an LED bulb, with the same wattage, shape and base, there would be a problem.

That never occurred to me either. That problem didn't arise the two times I installed chandelier LED retrofits, but they were both fairly low-end store-brand fans.

BTW, the LED bulb actually isn't the same wattage. The big print
on the package is "equivalent incandescent wattage." LED retrofits
typically use about 1/10 to 1/5 of the original bulb's power. And that may be the problem. Your fan controller may get confused by the retrofit's very low current consumption.

This might be comparable to what happened to me when I installed retrofit LEDs in my car's parking lights and tail lights. (I got annoyed with repeatedly replacing the incandescent bulbs. Why is it that factory bulbs last 6-8 years and replacements last 1-2 years at most?).

I looked out in the driveway that night and the taillights were glowing faintly. Spooky!

Turns out that cars no longer have real switches for most (all?) lights. The switch you flip or turn just signals the body computer, which does the actual control of the lights with a semiconductor switch. Unlike a real switch, which has essentially infinite resistance when open, the semiconductor has measurable resistance.

Without wanting to get too technical here, I'll just say that the LEDs' current draw was so low that a significant voltage remained across them when the "switch" was supposed to be off.

In your case, I guess you could buy a new fan controller from Minka Aire, but it might not be worth the expense.

If the fan were mine, I'd probably do some research on whether the controller was actually needed. If possible, I might just scrap it (or sell it used on Ebay) and connect both fan and light directly to old fashioned analog wall controls. But that's me. Sometimes I'm kind of a Luddite about such things.

This video shows how to convert the Minka Aire Concept II ceiling fan to LED: https://www.youtube.com/watch?v=suF1SCJ6G7A

Here is the part they used to do it:

https://smile.amazon.com/gp/product/B01MRHB47F/ref=ox_sc_act_title_1?smid=AKJ3LKLJP9ZCH&psc=1