Have tested cooker hood fan following to suppliers instructions and it is working. Problem is in the ducting. There is a flap inserted in outside wall and this does open as necesary, Supplier asked us to do A4 paper test when fan on withou duct attached and paper does 'stick' to all 3 mesh panels on hood. When flexible ducting hose attached to extractor inside chin=mney then paper does not stick and hood not extracting as should.
Who would be the best person/tradesman for the task?
