When it is done the heat cycle and around 10 to 12 minutes after the flame goes out the flame rollout switch will go open, triggering a code 33 and then to code 13. Reset the switch and everything is good. If I leave the front access panel of it will operate fine. Any answers.

Hi Don and welcome, sounds like your furnace is over-heating, has the filter been changed? Vents all open? Duct work in good shape?

Took the filter out, checked all vents, cleaned burner tubes & orfices, replaced flame rollout switch. Everything works as it should if I leave the front access Panel off. Put it back on the rollout switch will open about 10 min after the burners shut in and trigger a code 33 & 13.

Hi again Don, have you watched as the furnace does a cycle and shuts down? How long does the fan run after the burners quit? Can you post a picture?

Fan is still running when it goes to code 33. Checked the temp on the burner flues and the one next to the rollout switch is 90 - 100 F hotter than the rest. Made an orffice that is 1/8 in bore, original one is some where between 1/8 & 5/64 and it seemed to have cured the problem. Installed it in the first port up stream of the gas valve in the manifold as that is the flue that was the hottest.

Well that's a new one on me, good luck and be safe.