i had an engineer today to check my boiler before giving us boiler insurance,the boiler has been working fine but he found a fault on the on/off switch it was fine until he pressed it on and off,but then it would not stay on so he put bit of plastic to hold the switch on, then said it would cost £35 to fix,i declined and bought the part for £3.86 and fitted it myself,now everytime i put the new switch on it blows the 2amp fuse in the plug,does anybody know what might be wrong?i have also tried the old switch and its doing the same as the new switch, could i have knackered the pcb?wish i had paid the engineer now to fix it 
