227
Easy Fix
Lennox · HVAC Systems (AC, Furnaces & Heat Pumps)
3-Amp Fuse Open
Quick Answer
Error code 227 on your Lennox HVAC Systems (AC, Furnaces & Heat Pumps) means: 3-Amp Fuse Open. This is usually fixable — see the step-by-step guide below.
Affected Models
Applies to all models
Likely Causes
How to Fix It
1
Replace the 3A fuse on the control board with an identical rated fuse
2
Disconnect the thermostat R wire and test for shorts to other terminals
3
Isolate each control wire to determine which circuit is causing the short
4
Check zone damper motors and valves for short circuits if applicable
5
Verify thermostat current draw does not exceed the fuse rating
Pro Tip
This is a common issue that most users can resolve without specialized tools. Try the first step before moving on to more complex solutions.
Parts You May Need
3A fuse
Thermostat wire
Wire connectors
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