White Rodgers Thermostat 50A55-743 User Guide The 50A55-743 is an automatic gas interrupted ignition control that employs a microprocessor to continually monitor, analyze, and control the proper operation of the WHITE RODGERS 50A55 TROUBLESHOOTING MANUAL Pdf View and Download White Rodgers 50A55 troubleshooting manual online. INTEGRATED FURNACE CONTROL MODULE. 50A55 Controller pdf manual download. Also for: 50a55-143. WHITE RODGERS 50A55-843 USER MANUAL Pdf Download. Page 5: Typical System Wiring Table HUM N (optional) spade terminal * The twinning feature is available only on models with six screw terminals; one of these terminals will be designated “TWIN”. All 50A55-843 controls used in twinning applications must have the “TWIN” terminal.