We switched on one of the light switches in the kitchen (it controls 6 ceiling lights and is a variable light switch) and it triggered the mains fuse box (all downstairs lights switch). When I switched the downstairs light fuse box switch on again, the 6 lights did not come back on (although the other downstairs lights all did). I then replaced a couple of the 6 GU10 light bulbs but they didn't light up.
We subsequently found that Royal Electrical had wired the the switch incorrectly and only one set of lights would work. We called them back and, after a further visit (making 3 visits in all) they admitted they did not know how to wire up the switch as it had been wired up before. They apologised and refunded the money I had paid them. I called in another electrician who rewired the switch correctly in 4 minutes and it has been fine since.
We had two light fittings (each with 3 bulbs) from John Lewis installed in our living room by a qualified electrician. However they either immediately break the lightbulb, or the lights flicker on and off. We have never had all 3 lights stay on at the same time on both light fitings. Not sure whether they are both faulty, or just incorrectly installed.
Came quickly, did a good job, just expensive.