Description
Lennox R40403-003 Furnace Control Circuit Board – OEM Replacement for System Management
The Lennox R40403-003 Control Circuit Board is an original equipment manufacturer (OEM) furnace control board designed to manage ignition, blower timing, and system diagnostics in compatible Lennox heating systems. Acting as the brain of the furnace, this control board monitors safety sensors and coordinates multiple system components to ensure safe and efficient heating operation.
Whether you’re replacing a board due to error codes, ignition issues, or blower malfunctions, the R40403-003 provides a factory-calibrated solution for restoring full furnace functionality. Its plug-and-play compatibility makes installation straightforward for HVAC professionals and experienced technicians.
Key Features:
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OEM control board for Lennox gas furnaces
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Manages ignition timing, blower motor operation, and safety sequences
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Ensures proper integration with flame sensors, pressure switches, and gas valves
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Compatible with standard Lennox wiring harnesses for fast installation
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Resolves issues like intermittent heat, blower failures, or startup faults
Alternate / Replacement Part Numbers:
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R40403-001
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R40403-002
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20054501
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20054502
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ST9120C 2010
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1138-83-1002A
Built for long-term reliability, the R40403-003 circuit board is a smart upgrade for ensuring your Lennox furnace continues to deliver safe, dependable heat.
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