Hi all. I have a Glow Worm 30CXI installed in boiler cupboard upstairs. Since I've moved in I havent been able to get the timer to work properly on the boiler itself. The timer works - the clock is moving and you can hear it - but it doesn't work on the program timer. The boiler does function correctly for heating when set to permanently on. My conclusion is that the timer is knackered - confirmed by the glow worm support line who wanted over £300 to replace it. I spoke to a local parts supplier who could sell me the timer unit for approx 160 inc VAT (cant remember exactly it was over 6 months ago that I enquired). I'm content that I can install a programmer / thermostat in place of my current installation in downstairs hallway. The current stat has 3 wires - Live, Neutral and Earth. I've been looking through some of the old forum posts that talk about 2 wire installations, switched lives etc. I'm just a bit confused as to what to go for. In my head I just want a mains powered programmer and simply replace it. But I'm not a plumber so could be wrong. Finally - upon installing the programmer downstairs - would I need to remove the mechanical timer from the boiler (happy to do this myself - it seems to be easily removable). Many thanks for your advice.