Honeywell ST7800A1054 Purge Timer Card 60 Sec

The Honeywell ST7800A1054 is a plug-in purge timer card designed for use with 7800-Series primary controls and relay modules on gas furnace applications. It is a non-programmable, hardwired card rated for 120V, 60 Hz line voltage operation, providing a fixed 60-second pre-purge timing function within the ignition sequence. This card is intended for residential and commercial natural gas furnace systems and is not heat pump compatible. Installation requires a qualified professional given its role in the ignition control sequence. It addresses common failure symptoms such as furnace not igniting, ignition delay, purge cycle timing errors, and control board fault codes. As a plug-in module, it allows straightforward swap-out on affected primary controls without rewiring the base control.