Tim, go check the fault codes. You can do that in the dark.
(probably won't help much though)
Is the fuse seated correctly ?
If you get desperate give it another bleed.
I personally don't worry about driving with the light on but Richard don't like it.
P.S For others, Richard recomends using the bolt next to the temp sensor for level checking/breather during filling rather than removing the delicate temp sensor.