Lennox Air Conditioner Error Code E413

E413 means the high pressure switch in the refrigerant circuit has opened five times within one hour, and the outdoor unit has locked out to prevent compressor damage. The high pressure switch trips when discharge pressure exceeds a safe operating limit. Five trips in a short window indicate a persistent problem rather than a one-time event. A power reset will clear the lockout, but the fault will return unless the root cause is corrected.

The E413 lockout is a safety feature designed to prevent the compressor from being damaged by sustained high pressure operation. Running the system without addressing the fault risks compressor failure, which is the most expensive component in the refrigerant circuit. It is best to leave the system off and have a technician inspect it before resuming operation.

The first step is to connect refrigerant gauges and confirm the system is properly charged, since both undercharge and overcharge can cause high pressure faults. From there, the technician should inspect the condenser fan motor for correct operation, check the indoor blower motor and coil for blockages, evaluate TXV function through superheat measurements, and inspect the refrigerant filter for restriction. On heat pump models, the reversing valve should also be tested.

Yes, cycling power to the system will clear the E413 lockout and allow the outdoor unit to restart. However, if the underlying cause is not corrected, the high pressure switch will trip again and E413 will return, potentially within minutes. A power reset should only be used after diagnosing and resolving the condition that caused the repeated high pressure trips.

Repair costs depend entirely on the root cause. A refrigerant charge adjustment or a dirty coil cleaning may cost between $100 and $300. A TXV replacement or condenser fan motor replacement typically runs between $250 and $600 including labor. A reversing valve replacement or compressor repair, if damage has already occurred, can range from $600 to over $1,500 depending on parts and labor in your area.