I have a porch light that has a compact florescent bulb in. It is the type which is not a replacement for an ordinary tungsten filament bulb. This means that I can leave it on if I want to without using too much electricity. It is also controlled by a PIR so that if it is off it comes on when someone enters the porch so that they can see where the door lock is.
Now I know that a PIR/CFL combination is not necessarily recommended and I am not sure if the PIR is one sold as being suitable for CFLs. However it has worked fine for three or four years. PIR triggers. Light comes on, goes off, comes on again, goes off again and finally comes on for good.
Recently however it has started doing the opposite. Flashing on/off a couple of times and then staying off. It sometimes stays on so it is not a complete failure of the bulb. Nothing else has changed.
Any ideas please on why this might be happening now.
Andrew