HVACopediaLennox · Air handler
41 Device control board replaced
What the control is telling you
Appears whenever a communicating board is swapped out (AC, heat pump, furnace, air handler, damper module or PureAir S). S30/S40 alert code 41.
Applies to: Lennox communicating air handlers and EIM-equipped indoor units in S30/S40 smart thermostat systems
Likely causes
- Control board replacement
Test and repair steps
- Confirm the new control is configured (unit size code) and the system is recommissioned.
- Clear the alert manually in the dealer notifications.
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Source: Lennox Residential Communicating Systems Alert Code Guide (V2) 100017 (3/2023), Table 2 Alert Codes and Troubleshooting, p.13. 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.