Actually it's a code 4, smoke fan error. I had to replace the ignitor, so while I was at it did a deep clean. After reassemble, I get a smoke fan error within 15 seconds of the smoke fan starting. Fan runs very strong, I've cleaned the exhaust , took the fan out cleaned the blades and back plate. I was thinking i could do a factory reset, but can't find the passcode or where that might be in the menu. Anyone have any suggestions? There's a pressure guage just above the fan with an in and out tube. I was thinking i might adjust that. My set up, is 2 45's into a vertical that is close to 25 ft. through the roof. Hopefully someone has a great idea.