Lennox HVAC Error Code E39: How to Fix It

Q: Can I reset Lennox error code E39?

Yes, you can reset the error by turning off power to the unit for 30 seconds and then turning it back on. However, if the underlying issue isn't fixed, the code will reappear.

Q: How much does it cost to fix error code E39 on a Lennox furnace?

If you DIY, a pressure switch costs around $30-$80. Hiring a pro costs $150-$300 for diagnosis and repair. Inducer motor replacement is more expensive ($300-$600).

Q: Is error E39 serious?

Yes, it can prevent your furnace from operating and may indicate a safety issue with combustion gases. Do not bypass the pressure switch.

Q: Will error code E39 clear itself?

It may clear temporarily if the condition resolves, but if the underlying problem remains, the error will return.

Q: What does induced draft pressure switch do?

It senses negative pressure created by the inducer fan to confirm that combustion gases are being properly vented. It is a safety device.

Abstract

Lennox HVAC error code E39 indicates a problem with the induced draft pressure switch. This switch ensures proper airflow for safe combustion. The error usually means the switch is stuck open, closed, or has a wiring issue, or there's a blockage in the venting system.