One of the most common problems with a hot air popper is burnt popcorn. Burning may be a result of overfilling the unit past the "Fill" mark on the popping chamber or using stale popcorn kernels. Purchase yellow or white whole popcorn kernels for the best results. Some smaller or lighter popcorn kernels may not pop well and can end up burnt.
If you fill your hot popper to the fill mark on the popping chamber, you may be surprised if the overall volume of popped corn seems low. This issue may be due to cold popcorn, which dries out the kernels and can keep the kernels from popping correctly. Do not store popcorn kernels in a refrigerator or freezer -- instead, keep kernels in an airtight container.
If the popcorn maker gets clogged frequently during use, make sure you have not overfilled the popping chamber. Tilt the popper forward slightly during popping to help keep the corn exiting correctly during the process and to keep the chute from clogging.
If you use a metal bowl for the popcorn, the hot air that comes out of the popping chute can heat the bowl, as does the popped corn. This heat can result in a bowl that is too hot to touch and can even burn skin if touched. Use a plastic bowl instead and check the bowl for the "Dishwasher Safe" label to make sure it can handle heat without getting too hot.