Water In Diesel Warning Light

This means water needs to be drained from the fuel filter and should be drained ASAP.

How to Drain Water from Diesel Filter

Most diesel fuel filters will have a drain on the bottom of the filter (see picture), unscrew this one turn, with a container underneath, the water/diesel should pour out, if it does not undo the bleed screw on the top if fitted or remove a pipe on the filter, to allow the air into the filter, if a hand primer is fitted, pumping this might force the water/diesel out. If you look at the water/diesel in the container you will see the water on the bottom, as oil and water don’t mix. The vehicle should start up ok and bleed itself if not follow my guide to bleeding diesels.