I have a glow-worm boiler which I believe to be a balanced flue model (I do not have a users manual). It is mounted underneath a worktop in the kitchen but does appear to be wall mounted. It was working ok when I switched on the controller and selected hw and ch (the controller does not allow ch without hw. In other words the fan would not start and light up would not occur unless hw was selected). Now when I go through the start procedure the fan does not start, the boiler does not light up, but the circulating pump does start. I switched the boiler thermostat off and on but no joy there. I took the front off (4 screws) but all that did was to indicate that there is not a permanent piolt light but electronic ignition on demand. I got a Corgi plumber in who checked the wiring to the fan which had no power. He needed the users manual to check fault finding tips and went away to check with manufacturer. There is a wiring diagram on the inside of the thermostat housing cover which shows a fuse among other things (pcb,circ. pump etc.). Can anyone suggest possible causes and solutions for my problem? Also can I fix them myself or should I persist with my Corgi man and where can I view or download a manual?