231
Moderate
Lennox · HVAC Systems (AC, Furnaces & Heat Pumps)
Line Voltage Reversed
Quick Answer
Error code 231 on your Lennox HVAC Systems (AC, Furnaces & Heat Pumps) means: Line Voltage Reversed. This is usually fixable — see the step-by-step guide below.
Affected Models
Applies to all models
Likely Causes
How to Fix It
1
Use a multimeter to check voltage between hot and neutral, hot and ground at the furnace
2
Verify less than 2VAC between neutral and ground at the furnace connection
3
Inspect the wiring at the furnace junction box and correct any reversed connections
4
Check the disconnect switch or outlet wiring for proper polarity
5
A licensed electrician should be consulted if the issue is in the circuit breaker panel
Pro Tip
This fix requires some technical knowledge. If you're unsure about any step, consider contacting support or a qualified technician.
Parts You May Need
Electrical wire (14/2 or 12/2)
Wire nuts
Disconnect switch (if faulty)
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