Lennox HVAC Error Code E41: How to Fix It

Q: Can I reset error code E41 without fixing anything?

Sometimes a simple power cycle (turn off power for 30 seconds, then restore) may clear E41. However, if the fault is caused by a defective board or wiring issue, the code will return.

Q: What causes a secondary control board fault?

Common causes include power surges, loose connections, moisture damage, or component failure due to age. Lightning strikes or voltage fluctuations are frequent culprits.

Q: Is it safe to replace the control board myself?

If you have basic electrical knowledge and follow safety precautions (disconnect power, use a multimeter), replacing a control board is doable. Otherwise, hire a professional.

Q: How much does a replacement secondary control board cost?

Lennox secondary control boards typically cost between $100 and $300, depending on model. Labor for professional installation adds $150-$300.

Q: Will error E41 prevent my HVAC from running?

Yes. The secondary control board is critical for proper operation. Your system may not heat or cool until the fault is resolved.

Abstract

Error code E41 on a Lennox HVAC system indicates a fault with the secondary control board. This board manages communication between the main control board and components like the blower motor or reversing valve. The error can be caused by a loose connection, power surge, or a faulty board. This guide will help you troubleshoot and potentially fix the issue.