36-25R3744 Rotom Run Capacitor for HVAC Motors, Replaces a Failed 25 MFD Round Capacitor

Rotom 36-25R3744 is a single-section round motor-run capacitor rated at 25 MFD and 370/440 VAC. It helps maintain the electrical phase shift required for compatible HVAC, refrigeration and appliance motors to operate efficiently.

A weak, swollen, leaking or open capacitor may contribute to a motor that hums, starts slowly, overheats, runs intermittently or does not start.

Confirm that the original capacitor is a single-section 25 MFD run capacitor. Match the voltage rating, round case, terminal arrangement and available mounting space before ordering. A 440V-rated capacitor may replace a 370V capacitor with the same 25 MFD rating. Never substitute a different capacitance value solely because the capacitor fits physically.

Capacitors can retain an electrical charge after power is disconnected. Installation and testing should be performed by a qualified HVAC or electrical technician.

Is This the Right Part?

Replacement for compatible applications requiring a single-section 25 MFD round run capacitor rated 370V or 440V. Confirm the complete original capacitor specifications before ordering. Verify diameter and height before ordering because electrically equivalent capacitors may use a taller case.

Common Symptoms

• Motor hums but does not start or starts very slowly
• Motor overheats during normal operation
• Motor runs intermittently or shuts off unexpectedly
• Capacitor case is visibly swollen, bulging, or leaking

Check Before Replacing

• Confirm the original capacitor is a single-section run type — not a dual-run (two-section) capacitor. Dual-run capacitors contain an additional section and are not direct one-for-one replacements without application-specific wiring.
• Verify the original capacitance is exactly 25 MFD. Capacitance must remain exactly 25 MFD unless the equipment manufacturer specifies otherwise.
• Confirm the original voltage rating is 370V or 440V — never use a capacitor rated below the equipment’s required voltage.
• Measure the available mounting space and compare to the replacement dimensions: 1.78 in diameter × 3.54 in height (approx. 45 mm × 90 mm).

Part Details

Installation Notes

1. Disconnect and lock out power to the 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 and terminal connections before disconnecting.
4. Compare the new capacitor with the original — confirm capacitance, voltage, case shape, terminal type and physical dimensions.
5. Inspect nearby wiring, connectors and motor windings for damage while the capacitor is removed.
6. After installation, restore power and test the motor 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 appliance or equipment model number. It is suitable for compatible applications requiring a single-section 25 MFD round run capacitor rated 370V or 440V.

Fitment reminder: Match capacitance (exactly 25 MFD), voltage (370V or 440V), capacitor type (single-section run), case shape (round), terminal configuration and available mounting space before ordering.