Lennox 12L09 Flame Sensor
The Lennox 12L09 Flame Sensor is a critical genuine OEM replacement part engineered for precise flame rectification in Lennox residential furnaces and heating units. This HVAC flame sensor functions as a safety probe, generating a microamp signal to the integrated furnace control board to verify successful ignition of the burner assembly. If the sensor detects a loss of flame, it triggers a system lockout to prevent hazardous gas accumulation. Built with high-grade ceramic insulation and a durable stainless steel probe, the 12L09 ensures consistent furnace ignition diagnostics and eliminates common intermittent operation issues caused by carbon buildup or high-resistance oxidation on non-OEM components.
For technicians performing furnace maintenance, this sensor is a direct-fit solution for Lennox G24, G26, and G32 models, as well as various Elite and Merit series equipment. Replacing a fouled or cracked sensor with this 12L09 Lennox replacement restores factory-spec response times and prevents the nuisance service calls associated with "short cycling" or three-flash lockout codes. As a professional-grade heating system component, it maintains the UL certification of the equipment and ensures the reliability of the flame proving circuit under high-temperature conditions.
Key Benefits for Contractors
- Precise Signal Strength: Delivers the exact microamp output required by Lennox control boards to maintain continuous burner operation without false lockouts.
- High-Temperature Durability: Constructed with industrial-grade materials to withstand the intense thermal environment of the burner primary air path.
- OEM Compatibility: Pre-formed offset and mounting bracket ensure the probe is positioned correctly within the flame envelope for immediate rectification.
- System Security: Prevents unburned fuel from entering the heat exchanger by providing rapid feedback to the ignition module.
Common Questions
What are the symptoms of a failing Lennox 12L09 Flame Sensor?
Usually, the furnace will ignite for several seconds and then shut down. This often repeats three times before the control board goes into a hard lockout. If the porcelain is cracked or the probe is heavily oxidized, the sensor cannot return the necessary signal to the board.
Can I clean the 12L09 sensor instead of replacing it?
While cleaning with a fine abrasive may temporarily restore the signal, the protective coating on the probe eventually degrades. For long-term reliability and to prevent emergency no-heat calls, installing a new Lennox 12L09 is the recommended professional practice.
Does this sensor fit all Lennox furnaces?
No, this is a specific Lennox OEM part. You should verify your specific model number or consult the original parts manual to ensure the 12L09 is the correct probe configuration for your burner assembly.
Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.
Original: $11.92
-65%$11.92
$4.17Lennox 12L09 Flame Sensor
The Lennox 12L09 Flame Sensor is a critical genuine OEM replacement part engineered for precise flame rectification in Lennox residential furnaces and heating units. This HVAC flame sensor functions as a safety probe, generating a microamp signal to the integrated furnace control board to verify successful ignition of the burner assembly. If the sensor detects a loss of flame, it triggers a system lockout to prevent hazardous gas accumulation. Built with high-grade ceramic insulation and a durable stainless steel probe, the 12L09 ensures consistent furnace ignition diagnostics and eliminates common intermittent operation issues caused by carbon buildup or high-resistance oxidation on non-OEM components.
For technicians performing furnace maintenance, this sensor is a direct-fit solution for Lennox G24, G26, and G32 models, as well as various Elite and Merit series equipment. Replacing a fouled or cracked sensor with this 12L09 Lennox replacement restores factory-spec response times and prevents the nuisance service calls associated with "short cycling" or three-flash lockout codes. As a professional-grade heating system component, it maintains the UL certification of the equipment and ensures the reliability of the flame proving circuit under high-temperature conditions.
Key Benefits for Contractors
- Precise Signal Strength: Delivers the exact microamp output required by Lennox control boards to maintain continuous burner operation without false lockouts.
- High-Temperature Durability: Constructed with industrial-grade materials to withstand the intense thermal environment of the burner primary air path.
- OEM Compatibility: Pre-formed offset and mounting bracket ensure the probe is positioned correctly within the flame envelope for immediate rectification.
- System Security: Prevents unburned fuel from entering the heat exchanger by providing rapid feedback to the ignition module.
Common Questions
What are the symptoms of a failing Lennox 12L09 Flame Sensor?
Usually, the furnace will ignite for several seconds and then shut down. This often repeats three times before the control board goes into a hard lockout. If the porcelain is cracked or the probe is heavily oxidized, the sensor cannot return the necessary signal to the board.
Can I clean the 12L09 sensor instead of replacing it?
While cleaning with a fine abrasive may temporarily restore the signal, the protective coating on the probe eventually degrades. For long-term reliability and to prevent emergency no-heat calls, installing a new Lennox 12L09 is the recommended professional practice.
Does this sensor fit all Lennox furnaces?
No, this is a specific Lennox OEM part. You should verify your specific model number or consult the original parts manual to ensure the 12L09 is the correct probe configuration for your burner assembly.
Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.
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Description
The Lennox 12L09 Flame Sensor is a critical genuine OEM replacement part engineered for precise flame rectification in Lennox residential furnaces and heating units. This HVAC flame sensor functions as a safety probe, generating a microamp signal to the integrated furnace control board to verify successful ignition of the burner assembly. If the sensor detects a loss of flame, it triggers a system lockout to prevent hazardous gas accumulation. Built with high-grade ceramic insulation and a durable stainless steel probe, the 12L09 ensures consistent furnace ignition diagnostics and eliminates common intermittent operation issues caused by carbon buildup or high-resistance oxidation on non-OEM components.
For technicians performing furnace maintenance, this sensor is a direct-fit solution for Lennox G24, G26, and G32 models, as well as various Elite and Merit series equipment. Replacing a fouled or cracked sensor with this 12L09 Lennox replacement restores factory-spec response times and prevents the nuisance service calls associated with "short cycling" or three-flash lockout codes. As a professional-grade heating system component, it maintains the UL certification of the equipment and ensures the reliability of the flame proving circuit under high-temperature conditions.
Key Benefits for Contractors
- Precise Signal Strength: Delivers the exact microamp output required by Lennox control boards to maintain continuous burner operation without false lockouts.
- High-Temperature Durability: Constructed with industrial-grade materials to withstand the intense thermal environment of the burner primary air path.
- OEM Compatibility: Pre-formed offset and mounting bracket ensure the probe is positioned correctly within the flame envelope for immediate rectification.
- System Security: Prevents unburned fuel from entering the heat exchanger by providing rapid feedback to the ignition module.
Common Questions
What are the symptoms of a failing Lennox 12L09 Flame Sensor?
Usually, the furnace will ignite for several seconds and then shut down. This often repeats three times before the control board goes into a hard lockout. If the porcelain is cracked or the probe is heavily oxidized, the sensor cannot return the necessary signal to the board.
Can I clean the 12L09 sensor instead of replacing it?
While cleaning with a fine abrasive may temporarily restore the signal, the protective coating on the probe eventually degrades. For long-term reliability and to prevent emergency no-heat calls, installing a new Lennox 12L09 is the recommended professional practice.
Does this sensor fit all Lennox furnaces?
No, this is a specific Lennox OEM part. You should verify your specific model number or consult the original parts manual to ensure the 12L09 is the correct probe configuration for your burner assembly.
Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.
