ICM286 Furnace Control Board "manual goodman thermostat" Questions

...Goodman GMS90904CXA furnace was no longer providing 120VAC to my inducer blower so I got the ICM286 as a replacement. Install was simple but when I turned the system on and "called for heat" as soon ...

...Goodman GSK91155DXAC furnace with an ICM board. R, W, Y, G, and C are used. Everything works with exception of when calling for heat. An error code "8" shuts off the burners after a second or so. The ...