The White-Rodgers 50D50U-843 All-Spark Universal Ignition Module is an Intermittent Pilot/Direct Spark Ignition (IP/DSI) furnace control and universal replacement ignition board designed to replace numerous OEM ignition boards in gas furnaces, unit heaters, and rooftop HVAC equipment.  Operating on 18 – 30 VAC, 50/60 Hz with flame-sense microamp feedback, this universal 24-volt module provides consistent, reliable ignition performance and clear LED/status feedback in residential and light-commercial systems.
 
 
Engineered for fast setup and service, the 50D50U-843 features NFC tap-to-configure programming with a clearly marked “Place Device Here” pad, plus a QR code that links directly to the configuration app.  An onboard IP/DSI selector, integrated 3-digit/7-segment digital display with fault recall/erase functions, and labeled multi-position terminal strip make configuration and wiring straightforward.  The printed diagnostic legend and operating status table on the label enable quick, code-based troubleshooting of flame failures, gas valve issues, and lockout conditions right at the control.
 
 
This ignition module controls the gas valve, spark, and flame verification for intermittent pilot and direct spark systems while managing pre-purge, post-purge, and ignition-trial timing and is UL Recognized. White-Rodgers 50D50U-843 directly replaces Trane CNT3484 DSI module and is intended for professional installation following equipment and manufacturer specifications.