Tool · Error-code decoder
What does that furnace code mean?
Enter the brand, controller and the code exactly as shown (including the minor digit), or match the flash pattern. The meaning below is quoted from the manufacturer's own service label for that control — never borrowed from another family.
Pick the family that matches your rating plate, then enter the code. Not sure of the family code? Read the full model number inside the blower door — the rating-plate guide shows you where.
Every result on this page links to the full code page with its sources, safe observations and the exact manual reference. Nothing here replaces a diagnosis: a code is a condition, not a failed part.