Goodman GMP050-3 Furnace Parts & Repair

The Goodman GMP050-3 is a 50,000 BTU upflow gas furnace built on a compact three-ton blower platform, making it one of Goodman’s smallest residential gas furnaces and a common choice for smaller homes, additions, and conditioned spaces where a higher-output unit would oversize the load. Unlike its GMP100 siblings, the GMP050-3 uses a two-cell heat exchanger, a three-burner manifold (part B2526000), and a smaller 1/3 HP blower motor (B1340021S rated at 1050 RPM). Repair Clinic stocks genuine Goodman OEM parts for this model including igniter B1401018S and its upgraded replacement 0230K00001, control board B1809913S, flame sensor 0130F00010S, inducer motor B2959000S, and primary limit switch B1370912S rated at 240 degrees Fahrenheit. Browse the full Goodman furnace parts catalog and filter by model number GMP050-3 to see only parts confirmed for this platform.

What Makes the GMP050-3 Different from Other Goodman Furnaces

Because the GMP050-3 sits at the low end of Goodman’s output range, its components are specifically sized for the reduced combustion volume and airflow of a 50,000 BTU installation. The blower motor (B1340021S) draws notably less current than motors in higher-output siblings, which is why a “low circulator current” fault code on this model often traces to the capacitor CAP125000370RPS losing its 12.5 microfarad charge rather than a failed motor winding. The inducer motor B2959000S is matched to the two-cell heat exchanger’s draft requirements, and substituting an inducer from a larger GMP model would over-draft the heat exchanger and affect pressure switch calibration. For diagnostic guidance on fault codes specific to the B1809913S control board used in this model, the Goodman furnace troubleshooting guide walks through each blink pattern in detail.

Most Replaced Parts on the Goodman GMP050-3

Hot Surface Igniter

The GMP050-3 shipped with the silicon carbide igniter B1401018S. Goodman’s current OEM upgrade is the 0230K00001 silicon nitride mini igniter, rated seven times more durable than the original carbide element. On a 50,000 BTU furnace that cycles frequently in a small, well-insulated space, the igniter accumulates thermal cycles quickly. A cracked or open-circuit igniter causes the board to time out at the ignition stage and lock out the furnace. Never touch the element with bare skin during installation.

Control Board

The 9-pin HSI control board B1809913S sequences ignition, monitors all safety switches, and stores the LED blink fault code on the GMP050-3. Because this board is shared across several GMP models, a replacement must match the original part number exactly. Before ordering, document the current blink pattern. A fault code indicating ignition failure points to the igniter or flame sensor, not the board, in the majority of GMP050-3 service calls.

Inducer Motor

The GMP050-3 uses the B2959000S inducer motor, sized for the two-cell heat exchanger’s combustion gas volume. This is a different motor than the B1859005S used in GMP100 models. A bearing failure presents as a grinding sound during the pre-purge phase. Because the GMP050-3 cycles more frequently per heating season than a larger furnace in the same home, inducer bearing wear can occur sooner than in a higher-output installation.

Flame Sensor

The 0130F00010S flame sensor rod confirms combustion is sustained on the GMP050-3 by passing a micro-amp current through the burner flame back to the B1809913S control board. A sensor reading below 1.5 microamps causes repeated lockouts. Testing with a DC microamp meter before replacement separates a genuinely failed sensor from a gas pressure or weak-flame condition that would require a different diagnosis path.

Blower Motor B1340021S and Capacitor CAP125000370RPS

The 1/3 HP B1340021S blower motor is smaller than motors in GMP100 models, and its run capacitor CAP125000370RPS is rated at 12.5 microfarads rather than the 10 microfarads used in some higher-output siblings. A capacitor drifting outside its rated value causes the blower to start slowly or run at reduced speed, triggering the primary limit switch B1370912S. Always test the capacitor first before replacing the motor.

Primary Limit Switch

The B1370912S primary limit on the GMP050-3 opens at 240 degrees Fahrenheit and has a 7-inch sensor probe suited to the compact heat exchanger in the 50,000 BTU cabinet. A limit that trips consistently is almost always caused by airflow restriction, not a failed switch. Inspect the filter, clean the blower wheel, and verify all supply registers are open before replacing the limit switch.

Why Repair Clinic for Goodman GMP050-3 Parts

• Genuine Goodman OEM parts sized specifically for the GMP050-3 two-cell, 50,000 BTU platform — not generic parts shared across the full GMP range without size verification
• Goodman fault code guides and wiring diagrams available alongside every part listing
• Same-day shipping on orders placed by 9:00 PM ET so your heat is restored before the next cold night
• 365-day returns on uninstalled parts, no restocking fees

Goodman GMP050-3 Furnace Parts FAQ

What is the blower motor part number for the Goodman GMP050-3?

The GMP050-3 uses a 1/3 HP direct drive blower motor, Goodman part B1340021S, rated at 1050 RPM with 3 speeds. This is a smaller motor than those in the 100,000 BTU GMP100 platform. Always verify the part number on your motor label before ordering, as several GMP50 variants were produced across different production runs.

What causes a low circulator current fault on a Goodman GMP050-3?

A low circulator current reading typically points to a failing blower motor, a failed run capacitor CAP125000370RPS, a wiring fault in the motor circuit, or a control board relay that is not fully closing. Start by testing the capacitor with a digital meter. If capacitance is more than 10 percent below the 12.5 microfarad rating, replace the capacitor before condemning the motor.

How many burners does the Goodman GMP050-3 have?

The GMP050-3 is built on a two-cell heat exchanger with a 3-inch in-shot burner assembly, part B4022700, and a three-burner manifold, part B2526000. This compact burner configuration is what distinguishes the 50,000 BTU model from its larger GMP siblings on the same cabinet platform.

What primary limit switch temperature is the GMP050-3 rated for?

The Goodman GMP050-3 primary limit switch, part B1370912S, is rated to open at 240 degrees Fahrenheit. It is a 7-inch sensor designed for the compact heat exchanger in the 50,000 BTU model. If this limit trips regularly, restrict the investigation to airflow problems before replacing the switch itself.

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