LENNOX SL280UH / SL18XC1 SPLIT SYSTEM Wont Ignite
| CONF | DIAGNOSIS | ACTION |
|---|---|---|
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92%
CONF
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Hot Surface Ignitor
The Hot Surface Ignitor (HSI) is a resistive ceramic element that must reach approximately 2500 degrees Fahrenheit to ignite the gas-air mixture; these components fail over time due to thermal fatigue and microscopic fractures. When the inducer motor hums during the startup sequence, the control board energizes this element, but a fractured HSI results in an open circuit that prevents heat generation. Replacing this component restores the necessary glow-surface temperature required for the gas valve to safely release fuel for combustion. This is the primary failure mode for Lennox furnaces that fail to ignite despite the inducer motor running.
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VIEW ON AMAZON
#CommissionsEarned
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8%
CONF
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Secondary Circuit / Wiring Check
Inspect wiring harness.
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VIEW ON AMAZON
#CommissionsEarned
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DIY Repair Guide
Watch exactly how to replace the Hot Surface Ignitor.
// NOTICE:
This report is generated by an Agentic AI Engineer utilizing probabilistic modeling.
PartSniper is an automated parts recommender service. AI-generated results may not be correct. This data is not a substitute for professional engineering advice or manual inspection. Always verify part compatibility and disconnect power before any repair. PartSniper is not liable for inaccuracies, injury, or damage.