36-25-103744 Rotom Dual Run Capacitor for HVAC Systems, Fixes Weak Compressor or Fan Starting

Rotom 36-25-103744 is an oval dual-run HVAC capacitor rated 25/10 µF and 370/440 VAC.

The capacitor combines two run-capacitor sections in one case. The 25 µF section is typically connected to the compressor circuit, while the 10 µF section is typically connected to the condenser-fan motor circuit.

A weak or failed capacitor may contribute to a compressor or fan motor that hums, starts slowly, operates intermittently or shuts down on overload.

Confirm that the original capacitor is rated exactly 25/10 µF. The replacement voltage rating must be equal to or higher than the original rating. Also confirm the oval case dimensions (2.80 × 1.77 × 3.74 in), mounting clearance and terminal arrangement before ordering.

This is a specification-matched HVAC component and is not selected by appearance alone. Disconnect electrical power before servicing. HVAC capacitors can retain a hazardous electrical charge and should be tested and replaced by a qualified technician.

Is This the Right Part?

Fits applications requiring an oval 25/10 µF dual run capacitor rated at 370V or 440V, subject to dimensional and terminal verification. A 440V-rated capacitor can replace a 370V capacitor when both capacitance ratings match exactly. A lower-voltage capacitor must not replace a higher-voltage application.

Common Symptoms

• Compressor hums but does not start, or starts very slowly
• Condenser fan motor does not start or runs intermittently
• Outdoor unit shuts off on overload or trips a breaker on startup
• Higher-than-normal operating current draw
• Capacitor case is visibly swollen, bulging or leaking

Check Before Replacing

• Test the capacitor with a capacitance meter — compare both the 25 µF and 10 µF readings against the tolerance printed on the original label before condemning it.
• Confirm the original is rated exactly 25/10 µF — a capacitor with a different µF rating is not an acceptable replacement even when its voltage, shape or terminals appear similar.
• Verify the original voltage rating — a 440V replacement is acceptable for a 370V application, but a 370V-only capacitor must not replace a 440V-rated application.
• Confirm the oval case dimensions (2.80 × 1.77 × 3.74 in) and three-terminal arrangement fit the available mounting space before ordering.

Part Details

Installation Notes

1. Disconnect and lock out power to the HVAC equipment before servicing.
2. Safely discharge the original capacitor before touching any terminals — capacitors retain charge after power is removed.
3. Photograph the original wiring — note which wire connects to each terminal (C, FAN, HERM or equivalent labelling on the original).
4. Compare the new capacitor with the original — confirm both µF values, voltage, case shape, dimensions and terminal positions.
5. After installation, restore power and test both the compressor and condenser fan for correct starting and running behaviour.

Use a qualified HVAC or electrical technician when diagnosis or installation is outside your experience.

Verified Compatible Applications

This capacitor is selected by electrical and dimensional specifications, not by equipment model number. It is suitable for compatible applications requiring an oval dual-section 25/10 µF run capacitor rated 370V or 440V.

Fitment reminder: Match both capacitance values (exactly 25 µF and 10 µF), voltage (370V or 440V), capacitor type (dual-section run), case shape (oval), terminal arrangement and available mounting space before ordering.