A furnace diagnostic system includes sensors that monitor various functions of the furnace. Data generated by such sensors may be stored for subsequent transfer or may be transferred in real time via an infra red link to a remote handheld device with which an analysis thereof is performed. The handheld...http://www.google.es/patents/US6658372?utm_source=gb-gplus-sharePatente US6658372 - Furnace diagnostic system
