Lennox HVAC Error Code E13: How to Fix It

Medium 30-60 minutes Medium Severity Verified June 2026
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Error Code
E13
Brand
Lennox
Product Type
hvac
Severity
Medium
DIY Difficulty
Medium
Estimated Fix Time
30-60 minutes
Error code E13 on your Lennox HVAC system indicates that the compressor is not running. This can be caused by a faulty capacitor, wiring issues, a defective contactor, or a problem with the thermostat. Follow these steps to diagnose and resolve the issue safely.
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Tools You'll Need

How to Fix Error Code E13

  1. Turn Off Power to the System

    Always disconnect power before servicing HVAC equipment to avoid electric shock.

  2. Check the Thermostat Settings

  3. Inspect the Contactor

    Be careful near high-voltage components even after power is off; capacitor may still hold charge.

  4. Test the Capacitor

    Capacitors can store dangerous electrical charge. Discharge properly before handling.

  5. Check Wiring Connections

  6. Test the Compressor Windings

    Only perform this test if you are comfortable with electrical diagnostics. If unsure, call a pro.

Parts You May Need

Run capacitor (matching microfarad rating)
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Contactor
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Run capacitor (matching microfarad rating)
Check Price on Amazon
Contactor
Check Price on Amazon
Run capacitor (matching microfarad rating)
Check Price on Amazon
Contactor
Check Price on Amazon
Run capacitor (matching microfarad rating)
Check Price on Amazon
Contactor
Check Price on Amazon
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When to Call a Professional

If you are not comfortable working with high-voltage electrical components, or if the compressor windings test shows a fault, call a licensed HVAC technician. Also, if the contactor or capacitor replacement does not resolve the issue, professional diagnosis is recommended.

Frequently Asked Questions

What does Lennox error code E13 mean?
Error code E13 means the compressor is not running, which can be due to a faulty capacitor, contactor, wiring issues, or a defective compressor.
Can I fix Lennox error code E13 myself?
Yes, if you have basic electrical skills and tools. Steps include checking the thermostat, contactor, capacitor, and wiring. However, if the compressor itself is faulty, you should call a professional.
How much does it cost to fix Lennox error E13?
DIY repairs cost around $10-$50 for a capacitor or contactor. Professional repair may range from $150-$300 for diagnostic and parts, plus labor.
What causes a Lennox compressor not to run?
Common causes include a failed start or run capacitor, a defective contactor, loose wiring, a bad thermostat, or a seized compressor.
Is it safe to replace a capacitor on an HVAC unit?
Yes, if you discharge the capacitor properly and turn off power. However, if you are unsure, hire a professional to avoid electric shock.

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