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Lennox · Heat pump

15 Parameter mismatch detected

Low severity

What the control is telling you

Incorrect parameter settings were found (information for dealer only). S30/S40 thermostat alert code 15.

Applies to: Lennox communicating heat pumps incl. variable-capacity inverter units in S30/S40 smart thermostat systems

Likely causes

  • Configuration settings do not match the installed equipment

Test and repair steps

  1. Reset the system and run the configuration again.
  2. Clears automatically when configuration is completed correctly.

Settings for these units

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Source: Lennox Residential Communicating Systems Alert Code Guide (V2) 100017 (3/2023), Table 2 Alert Codes and Troubleshooting, p.9. Summarized in our own words; check the original manual for your model.

Homeowner looking at this code? See what it means for you and when to call a technician.

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.