This week I had a rangehood installed and the fans work at different speeds but there is almost 0 suction even though the extraction should be between 2000-3000m3/hr. I tested the suction placing a piece of paper directly under the filters and there was no suction. I removed the filters and placed the paper directly onto the fan and it stuck momentarily but then fell off.
What are some possible reasons for this? What are some things I can check determine if the error is due to installation or if the product itself is faulty.