LENNOX SLP98V Furnace Blowing Cold Air
| CONF | DIAGNOSIS | ACTION |
|---|---|---|
|
86%
CONF
|
Flame Sensor
This component uses the principle of flame rectification to confirm a burner flame is present. Over time, oxidation or carbon buildup creates an insulating layer that prevents the flow of micro-amps to the control board. The system then enters a safety lockout, shutting off the burners while keeping the blower running to purge the chamber, resulting in cold air output.
|
|
|
8%
CONF
|
SureLight Hot Surface Igniter
The igniter is a high-resistance ceramic element that reaches temperatures over 2,500°F to ignite the gas-air mixture. Due to thermal fatigue and high-cycle stress, the element can develop microscopic fractures that break the electrical circuit. If the igniter fails to glow, the gas valve is never commanded to open, but the blower will continue to circulate unheated air.
|
|
|
6%
CONF
|
Primary Limit Switch
This is a normally closed bimetallic safety switch designed to open if the heat exchanger exceeds its maximum rated temperature. If the switch fails in the open position or is tripped by poor airflow, it breaks the circuit to the gas valve. The furnace control board is programmed to run the blower motor indefinitely in this state to protect the heat exchanger from structural failure.
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DIY Repair Guide
Watch exactly how to replace the Flame Sensor.
// 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.