I fix roll laminators for a living, the heat from the bottom heater will tend to heat the upper one, but not hot enough to stick. Check and make certain all the heaters are plugged in. you will ,likely find a terminal off or loose, perhaps melted. If your within driving distance to pittsburgh I will come and give you a FREE ESTIMATE
bob haller service and sales pittsburgh pa 412 366 4906, March 2012