Dimmers present a challenge to ordinary low energy (compact fluorescent) lamps. There are two options here - to buy dimmable CFLs or some LEDs are now dimmable - though these tend to be quite expensive.

The other option is to replace dimmer switches with conventional ones. In many cases, either one action or the other will need to be taken, as conventional lightbulbs become more difficult to obtain. Take advice from a suitably qualified electrician on changing light fittings.

Sometimes dimmer switches are found in the cables for non-fixed lamps such as standard lamps and uplighters. It is usually straightforward to take out the dimmer control and replace it with the plug, but take advice if you are unsure.