White Rodgers Universal 50A55-843 and 50A65

White Rodgers Universal 50A55-843 and 50A65-843 Furnace Control Boards Trane XE80 Furnace Control Boards as well as many other brands (see cross reference below)

The main difference between these two controls is that the 50A55-843 is a Universal control made for replacements in Silicon Carbide Hot Surface Ignition systems which are found in most of Trane's lower end model furnaces. Most others manufacturers use this system in their lower end units.

White Rodgers 50A55-843 Universal Control MP (L39-566) White Rodgers 50A65-843 Control MP (L39-567)

Universal Silicon Nitride Integrated Ignition Control

White Rodgers Part # 50A65-843

Type Number 50A65-120 50A65-143 50A65-288 50A65-474 50A65-843

Pre-Purge 15 30 0 0 30

Trial for Ignition 4 4 4 4 4

Ignition Activation Period 4 4 4 4 4

Retries 4 times 2 times 2 times 2 times 2 times

Valve Sequence Period 20 12 12 12 12

Interpurge 15 60 60 60 60

Post-Purge 5 5 15 5 15

Lockout Time 250 300 300 300 300

Heat Delay-to-Fan-On 45 15, 30, 45, 60 30 45 30, 45

Source