In article .com,
wrote:
I have two 40W bulbs in my lounge on a double switch. I replaced the
switch for a double dimmer.

All was ok for a while until one of them started to flicker rapidly as
I turned the dial up from about 2/3 to full, the flickering got faster
as the dial was rotated closer to full, but below the 2/3 mark, the
bulb appeared steady.

First thing I'd look at is the *minimum* load requirement. As a rough
guide it's

40 watt for a 250 watt dimmer
60 watt for a 400 watt one.

But it should be somewhere on the packaging or instructions.

--
*A day without sunshine is like... night.

Dave Plowman London SW
To e-mail, change noise into sound.