glowworm f55 fan problem?

Hello

we have changed the fan on the f55 Glow-worm as it was stuck, it did move after a bit of wiggling and for a while and the boiler fired.

we have changed the fan and now no power seems to be getting to the fan (multimeter test) does anyone know of any common problems when changing these fans?

we have already changed the pump

This boiler is fast resembling "triggers Broom"

any help much appreciated