Furnace mounted horizontal in crawl space, relpaced filter and high limit swwitch and it still gives 4 flashes, ghi limit error still. Tried clearing condensate drains. Seems like high limit switch is wired in parallel with pressure switch and a switch in the area where the ignitor is. COuld any of these other switches be bad ? Or does 4 leds only mean the hig n limits switch? Are there other things that could be causing the high lmi switch when the furnace is not even firing?

THanks
Bruce