Hallo.

We have two roughly 6" square air vents in the kitchen wall, one near
the ground and the other a couple of feet up. There used to be an
oil-fuelled boiler in a concrete cupboard in the kitchen, but now the
only thing that needs ventilating in that room is the gas hob. Would it
be ok to brick up one of the vents, as they're quite draughty, or does
the hob really need that much fresh air?

Matt.