I have the same problem! I have just been on sime's website sime.ltd.uk and downloaded a manual, I don't think it's the exact right one but it has helped a bit. I think this is correct: to set the timer, grip the outside of the dial and turn it until the white pointer is lined up with the correct hour (the current time) shown on the outside of the dial. Then, slide the markers to the outside of the dial for the times you want the heating to come on. For the times the heating can be off, the markers should be at the inside of the dial. Then make sure the slider is at the '0' position, where the clock face is.
Hope this helps, I have only just done it on mine so not completely sure if it will work. But check out sime's website, under the technical bit.
Holly, November 2005
