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Lennox · Furnace

E151 A2L sensor fault

High severity EL296UHVLennox SL280UHVLennox ML180UHE

What the control is telling you

Listed in the 107045-XX table as an A2L refrigerant sensor problem (communicating mode only); no action text given. The manual (including its troubleshooting section) gives no corrective procedure for this code; steps are general checks only.

Applies to: EL296UHV(X) series furnaces with integrated control 107045-XX only

Likely causes

  • A2L sensor failed or disconnected

Test and repair steps

  1. Check the A2L sensor connector and wiring at the control.
  2. Refer to the A2L sensor literature for testing/replacement; this furnace manual provides no procedure.

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Source: Lennox EL296UHV(X) Unit Information / Service Literature, Ignition Control 107045-XX Diagnostic Codes table, p.41. Summarized in our own words; check the original manual for your model.

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For licensed technicians. Gas, electrical and refrigerant work must be done by a qualified, licensed person. Shut off power and gas before servicing, never bypass a safety control, and follow the manufacturer’s manual for the exact model; it and local codes always take priority. HVACopedia is not affiliated with any manufacturer; brand and model names only identify the equipment.