OL
York · TM9V100C20MP11 100,000 BTU 96% AFUE 2-Stage Variable-Speed Gas Furnace
The limit switch has opened due to excessive temperature or a faulty switch, causing the furnace to shut down to prevent damage. This error indicates airflow issues or a defective limit switch.
Error OL on the York TM9V100C20MP11 100,000 BTU 96% AFUE 2-Stage Variable-Speed Gas Furnace means: Open Limit Switch. The top-ranked community fix is “Replace Limit Switch” (medium difficulty, ~30 min, DIY cost: $25-$40). 2 community-ranked fixes available below.
Published February 2026 · 2 fixes · furnace
Content is based on manufacturer service documentation, community repair experience, and OEM technical bulletins. Always verify with your owner's manual.Learn about our editorial standards.
While many furnace repairs can be done safely at home, consider hiring a qualified technician if:
Average professional repair cost for this issue: $110-$170.
The York TM9V100C20MP11 100,000 BTU 96% AFUE 2-Stage Variable-Speed Gas Furnace has 8 other known error codes:
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