Lennox HVAC Error Code 350

Error code 350 on a Lennox air handler means the electric heat has not been configured in the unit's control system. The air handler cannot detect or operate its electric heat stages until the configuration is completed. This is a setup issue, not a component failure. The fault clears automatically once electric heat is successfully detected after configuration.

No, simply resetting the system will not clear code 350. The fault returns whenever the air handler fails to detect a configured electric heat setup. The only way to permanently clear the code is to complete the electric heat configuration in the control settings so the system can detect it successfully.

If the fault is simply a missing configuration step, the cost is typically limited to a service call fee, which generally ranges from $75 to $150 depending on your area and technician. If the underlying issue involves faulty wiring or a failed control board, repair costs can range from $150 to $600 or more depending on parts and labor required.

Clearing code 350 requires accessing the air-handler's control configuration interface to enable and define the electric heat settings. This process involves working with HVAC control systems and, in some cases, high-voltage electric heat components. Most homeowners should contact a qualified HVAC technician to complete this configuration safely and correctly.

Code 350 is primarily a configuration fault and does not indicate a dangerous condition in the way that an overheating or pressure fault would. However, it does mean your electric heat is not operational, which can leave your home without adequate heating. Addressing the fault promptly ensures the system can provide heat when needed.