R40403-003 – CONTROL BOARD (ST9120)

If your furnace won’t ignite, shows error codes, or the blower won’t start, the control board controls all of it. The R40403-003 replaces older ST9120 series control boards (A, B, C, and G models). Manages blower motor timing, inducer motor operation, ignition sequencing, and safety shutoffs.

Specs: Integrated furnace control, replaces ST9120A/B/C/G series

Replaces: R40403-003, ST9120C2010, ST9120G2008, 1008773, 1160192, 1170063, 20054502, HQ1008773HW

Fits: Furnaces originally equipped with ST9120-series control boards (Heil, International Comfort Products, Tempstar, and others)

Need help? See our Furnace Not Heating Guide.

In stock at Open To Public HVAC Parts in Dallas. We test parts at the counter before you buy. Call or text (214) 340-9421.

Cross-reference numbers

This part replaces the following OEM and aftermarket numbers:

• 1008773
• 1160192
• 1170063
• 20054502
• HQ1008773HW
• R40403-003
• ST9120G2008

Not sure if your number matches? Call (214) 340-9421 or bring the old part in — bench-testing is free.