Just off to Bunnings to get some flywire to place over the batts/pads as I have just read on another forum that someone tried that with success. I am not the handyman but i will give it a try.

Yes I will post a response as soon as he has been. Had the same problem last year but not as bad. I have cleaned out the tank and cleaned the batts in the last 3 weeks but still no difference.

Yes having the same problem for weeks now. I do not have a Brivis unit though. I have been given advice from placing bleach in the water tank to spraying outlet vents from inside the house with Bagon or similar. At this stage no luck with both. My air conditioner friend hopefully will come this week...