Found unit would not heat and not displaying errors. Upon checking found fuse on interface board blown jumped out and unit heated. Also has burnt fuse. Module is the cause for fuse to blow. Will need fuse, relay and module. Got an inline fuse and installed it temporary to get unit running, found unit heats good at this time. 2/26/18 Installed module, relay and fuse. Tested okay, customer will keep an eye on unit and let us know.