Gas dryer is 7 months old. Inlstalled in new house. Has been drying just fine until the last couple of days. It took 3- 60 mts cylcles to finally dry average load. Wet lint is accumelating around outside of lint screen. Repair man came today and took the dryer a part and insisted dryer is working just fine. He thinks that there could be a ventallation problem from inside the wall that connects to outside since the house was recently built. The lanundry room is on the second floor so he couldn't locate the exact spot of outside vent but from what he saw that maybe the vent opening, there were no smoke blowing out. Can someone suggest what might be wrong all of a sudden? I'm going to contact the builder tomorrow but if the problem turns out to be what he thinks, how is this problem usually resolved. Does it call for tearing any walls down. Really worried, please help if you are familiar with this. Thank you in advance.