havent worked on may Bryants but this Plus 90i is horizontal left in one tight spot! There is no model or serial anywhere but it has to be a 340-AAv or 350-AAV or MAV. ANyway it continues to trip out on the manual reset rollout switch. I confirmed clear combustion and flue exhaust pipes and no restrictions in return air and all supply vents open. blower is operational. The enclosed burner box does get quite hot when it trips so I'm sure switch isnt weak. homeowner hasn't had it running for about 2 years (using other heat in house)

any suggestions on this one??