Bosch under bench oven light ENr HBN111250A/01 type HTHB13?

try tightening it up first,this loosens the thread then turn anti-clockwiuse and as you have been told make sure you wear gloves

gts
January 2015

The bulb is situated in the centre of the roof of the oven, it is covered with a glass cover which unscrews, (must be that " bulgy protuberance" you described) it is usually quite tight to remove. There is a special plastic tool to make it easier if not you can try a jam jar lid remover.Wear thick leather gardening type gloves as sometimes it cracks all way round middle leaving a sharp edge. cleaning the roof you will have to work around the element as it does not come out .cheers

Kenjo
January 2015