vent bricks

[littlewil]

Im hoping someone can shed some light and this is posted in the right place. In my kitchen i have one vent brick (if the correct name for it) near the ceiling and one just above the floorboards, from what i have found out these were used to vent the boiler that used to be in this corner of my kitchen the boiler is now in the loft. So i was wondering what the best procedure was to fill these up without getting any problems in the future i was thinking of expanding foam. Just to add i also have smaller vents around the house which are below the floor boards so the house will still be able to breathe correctly.

Any advice much appreciated

 

[BBSBuilding]

Air vents are not just for boilers, they also stop condensation and mould build up. You could end up with a damp problem.
I would suggest maybe blocking one and put an open/close vent cover on the other.
You are more likely to get problems if you have solid brick walls.
where the cold from the wall meets the warm air of your house, a condensation can form causing mould. Air vents will help to stop this.