Extractor fan - blowing steam back into kitchen?

podge018

My extractor seems to be doing the opposite of what it should for some reason. It has worked fine for a year, then this happened out of the blue. When I turn it on, the steam comes towards me pretty strongly, there's a good gust blowing out of the fan.

Any ideas why this is happening?

Xcellor

Well if there isn't anywhere for the air to go it will come back. Perhaps you have a blockage on your external vent. You should turn it on and check if you can feel any air coming through.

If nothing has been modified I can't understand why the fan would change direction...

X

Moanin

maybe the pipe going from the fan to the outlet on the wall has come loose?

podge018

it's an apartment in a block of 8. It's going to be pretty tricky to find out isn't out? I don't even know where the external vent is.

podge018

Update

I took the hood/cover off it last night and held a piece of tissue to the fan. It's working properly.

The problem is where the fan casing meets the wall, there is air coming back in there and down the wall. So it's going and out and back in. Any ideas on why this is happening, and only now after a year?

podge018

There's a picture of the problem for anybody finding it difficult to know what's wrong.

10-10-20

Does it vent externally at all?
Some of these units are just air scrubbers, designed to filter and return air back, but I would have expected to see the return pipe above the shelf unit, not under it...

podge018

i've no idea where i'd even check. Like I say, it's a 4 storey apartment block with 2 apartments on each floor.