211
Moderate
Lennox · HVAC Systems (AC, Furnaces & Heat Pumps)
Ignition Failure
Quick Answer
Error code 211 on your Lennox HVAC Systems (AC, Furnaces & Heat Pumps) means: Ignition Failure. This is usually fixable — see the step-by-step guide below.
Likely Causes
How to Fix It
1
Check gas supply valve is in the ON position
2
Remove the igniter and measure resistance (silicon nitride: 40-200 ohms; silicon carbide: 40-75 ohms)
3
Visually inspect the igniter for hairline cracks or white discoloration
4
Verify 120VAC is present at the igniter terminals during the ignition sequence using a multimeter
5
Check gas manifold pressure with a manometer (3.5 in WC for natural gas, 10.0 in WC for LP)
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
Hot surface igniter
Gas valve
Igniter mounting gasket
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