Did the job, easy no probs for 3 months now. Bought Diaphram kit £8.00 which came with new brass nut and seal and a small grommit. Switched off water mains/power to boiler and removed front switch and nut(carefull to stop water falling on PCB), cleaned rod and slid on grommit with silicone grease. Reassembled and switched on water and power. Leak fixed!
Darren
March 2007