This is NOT a DIY question. I am a professional contractor C.E.T. (Canada, Certified Engineering Technologist). I just don't have these Trane codes in my back pocket and the local Trane distributor is closed today. Probably getting ready for the Super Bowl.
Need help with the fault codes for a Trane XR80, specifically code 21. This furnace is in the home of an older relative and I don't want them to remove the blower door to read the codes in case they don't get it back on properly before I get there.