HL
York · TM9V100C20MP11 100,000 BTU 96% AFUE 2-Stage Variable-Speed Gas Furnace
The high limit switch has opened due to excessive temperature inside the furnace heat exchanger. This safety device prevents overheating and shuts down the furnace until the condition clears.
Error HL on the York TM9V100C20MP11 100,000 BTU 96% AFUE 2-Stage Variable-Speed Gas Furnace means: High Limit Switch Open. The top-ranked community fix is “Replace High 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: $120-$180.
The York TM9V100C20MP11 100,000 BTU 96% AFUE 2-Stage Variable-Speed Gas Furnace has 8 other known error codes:
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