A hard start kit is a capacitor and relay used to give a Central Condenser compressor an extra boost of torque during startup. This is often used on older systems or units struggling with low voltage to ensure they start quickly and reliably. While our modern Inverter Systems usually don't need them due to their soft-start nature, they are common in traditional ducted repairs. You can find these and other electrical Replacement Parts in our catalog. If your unit is making a loud buzzing sound and failing to start, a hard start kit might be a temporary fix. However, it’s often a sign that it may be time to upgrade to a High-Efficiency Wall Mount. We provide technical guidance on these issues in our Help section. It is a useful tool for extending the life of a struggling motor in certain applications.