UNPLUG THE MACHINE! Check exhaust hose for kink or clog from where it connects to the machine to where it ends. If it ends on the roof you can vac the area where it goes into the wall. On the roof, make sure that a bird or rodent hasn't built a nest in the vent pipe. Also. if there is no screen on roof vent, put one on. Vac the lint filter and the area that it is attached to. Run a vent cleaner tool. If this doesn't work, check the heating element visually. It's easy to see if it is burnt out and not hard to change. Do not try and repair the coil with a piece of wire. or twist the coiled wire together. While you are in there, vac that area, too! Last but not least...check these areas once a month (put it on the calendar!!!) especially the area where you found the problem. Hope this helps.