Lennox Furnace Error Code 4 Flashes
Open high temperature limit — the limit switch isn't closing properly.
⚠️ Symptoms You'll Notice
- • Furnace shuts off after running
- • Heat cuts out
- • System cycles on and off
- • Temperature won't reach setpoint
What Causes Error Code 4?
🔧 DIY Troubleshooting Steps
- 1 Check air filter and replace if needed
- 2 Verify return vents aren't blocked
- 3 Look for loose connections to limit switch
- 4 Let furnace cool and reset
📞 When to Call a Professional
Limit switch testing and replacement needed.
Estimated repair cost in Albuquerque: $150–$400
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Frequently Asked Questions
What does Lennox Furnace error code 4 mean? ▼
Open high temperature limit — the limit switch isn't closing properly.
How much does it cost to fix error code 4 in Albuquerque? ▼
Typical repair costs in Albuquerque for Lennox Furnace error code 4 range from $150–$400. Limit switch testing and replacement needed.
Can I fix Lennox error code 4 myself? ▼
Some basic troubleshooting is safe to try: Check air filter and replace if needed. Verify return vents aren't blocked. Limit switch testing and replacement needed.
Other Lennox Furnace Error Codes
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