never worked one a worcester 350 before its the one with 2 pumps and no diverter valve.
hot water works fine heating fires up on demand but keeps cutting out at a low temperature so rads are luke warm,pump is fine and system is clear as sometimes it will work and rads heat up fast. any ideas??

horrible horrible boiler

the fan has a resistor to it that cuts the fan down low after two seconds and if its knackered or on its way out the boiler will intermittently not work on heating

with these boilers it could be one of a hundred things, if you ring Worcester there no help at all, unfortunately if you find its a pcb problem you have to change both according to Worcester bloody Bosch

good luck personally i would fire it in to the sun from a cannon