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Rectangular HVAC control module with circuit board and terminal connectors

KXINXIANG

KXINXIANG 50A66-743 HVAC control

SKU CH-1G3H-V9GQ6

OEM replacement module for Lennox furnaces with diagnostic flash codes, three fan speeds, remote flame sensing, and optional humidifier and electronic air cleaner connections

  • Product typeTools & Home Improvement›Building Supplies›HVAC›HVAC Control
  • Diagnostic flash codes simplify troubleshooting
  • Three fan speeds match comfort needs
  • Remote flame sense verifies ignition
  • Optional humidifier connection adds moisture control
  • Optional electronic air cleaner link improves air quality

Direct replacement control board

The KXINXIANG 50A66-743 serves as an OEM replacement module for Lennox furnace systems. It integrates diagnostic indicator flash codes to simplify troubleshooting for HVAC technicians and installers. The board supports three fan speeds and provides remote flame sense capability for reliable ignition monitoring. Optional connections are included for humidifier and electronic air cleaner accessories.

Sustained heating cycle stability

During continuous furnace operation the board maintains consistent fan-speed transitions across all three settings. The remote flame sense circuit continuously monitors burner status without signal drift over extended cycles. Diagnostic flash codes remain active throughout long heating calls, giving technicians real-time status without interrupting the sequence. Optional accessory relays for humidification and air cleaning switch cleanly under sustained load.

Upgrades legacy single-speed modules

This control replaces older furnace boards that lack multi-speed fan control or integrated diagnostics. The jump is worthwhile when the existing module cannot drive a humidifier or electronic air cleaner directly. It is not suited for systems requiring proprietary communicating thermostat protocols or variable-speed ECM motor algorithms not supported by this board.

How it compares

Measured against everything we stock in Heating & Cooling Controllers, at today’s prices. Recalculated every night.

Price $117.99
Pricier than about 72% of the 1,762 comparable items (median $45.99).

Specifications

Product
Product typeTools & Home Improvement›Building Supplies›HVAC›HVAC Controls

Questions about this item

Does the 50A66-743 module run hot or draw much power when the furnace cycles all day?

The control board is a low-voltage logic module; its own heat output is negligible compared to the furnace blower and burner.

What existing furnace components must be present to install this 50A66-743 replacement board?

You need a compatible low-voltage transformer, a flame sensor rod, a blower motor that supports three speeds, and the original wiring harness.

Will the 50A66-743 work with an older Lennox furnace that still uses a standing pilot?

This board is designed for hot-surface or intermittent-pilot ignition systems with remote flame sensing, not for standing-pilot configurations.

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