Discussion Starter · #1 ·
Anyone currently on to help with above furnace. Was shot cycling at a max run time of 4 mins. Changed limit switch and problem persisted. Pulled pleated merv 7 filter an ran filterless (contractor approved as test measure), ran for 13 mins straight until I manually shut it down (at thermostat). Put in mer 5 bare bones filter, manually shut it at 9 mins. House was hot now so didn't call for heat for a while. Cleaned flue run back to unit & vacuumed around unit back. All was fine until 12 last night. Locked out twice due to over cycle. 2 steady red flashes. Rand a few times blowing cold air. Cleaned what I thought were 2 flame sensors (little looped items in upper corners of gas supply bar, then is ran ok. Woke up to cold air again. Thoughts?