Hi; Need some advice about fault on Worcester 24i that's packed-up...not surprising as its been very reliable for 18 years!. Only ever replaced heating pump and pressure and flow switch over years but now can't get DHW or CH. Powr light on steady, fan starts and seems to rev up fine. Heating pump running fine during programme and pressure switch seems to be working (clicks when fan starts to run & both pipes clear) Water pressure ok 1.5 bar and steady. Get some clicking from pcb controls but no ignition. Problem originally started about 10 days ago - heating became intermittent when on. HW seemed fine, not really noticeable for loss of temp but did occasionally need tap turning off and then on again to get demand of HW. There is a sensor internally strapped to CH feed with 2 red wires to pcb. Touching this got the boiler working again for a short while but stopped firing-up at all this evening. Has anyone got any tips or knowledge of this type of problem?