I have two furnaces - one for each floor. One of the furnaces that were replaced within a year keeps blowing cold air randomly. I would reset it by turning the main power switch off/on and then it would work for a while and stop working again with either a 13 or 31 code. This Payne unit seems to have a bad limit switch.
So, a furnace flue gentleman came out and inspect my piping and found something interesting. The path looks clear, but he found a "ducting" with coils that appear smaller than what should be in there. This causes hot air to accumulate and hit the limit switch after some time. Let me attach pictures here. This is a 90,000 BTU unit.
Thoughts? Bad install? Common in the field? I am not an expert so feel free to correct my terminologies or put me in my place :)