When I checked the plenum drain a few weeks back I noticed then that the pollen filter looked a bit ropey and probably well overdue for a change. You can see from the photo the difference – yes they are the same size it’s just the angle of the camera!
The old one was loose and not properly held in position but when I put the new one in the clips again would not grip and hold the new filter in place – the same as the one I just removed. No matter what I did they kept slipping off the locating pegs.
Not sure whether the cover that sits over the plenum holds the clips in position …… but not wanting to leave it loose I carefully drilled a 3mm hole through the clip into the edge of the filter case avoiding the filter elements. Then thread a small plastic grip through the holes to hold the clip down onto the filter.
Job done …….