Multi-Brand Hard Start Kit Parts — AC & Heat Pump Compatibility

Your AC compressor struggles to start on hot days, making that grinding sound before it kicks in — or worse, it hums but never starts at all. The SPP6 hard start kit is a universal solution that works across Carrier, Goodman, Trane, Rheem, Lennox, and York systems. This single replacement part covers dozens of model series from major manufacturers, making it the go-to fix for compressor start failures.

Is This the Right Part for Your Model?

The SPP6 replaces hard start kits TJ90HS6, AP4502872, 35702, DST-6, ERPP6, HS6, and HS650. If your outdoor unit has a hard start capacitor that's failed — or your tech recommended adding one to help an aging compressor — this kit fits most residential AC and heat pump systems. Check your outdoor unit's data plate for the model number, typically located on the side panel near the electrical access cover.

About This Replacement Part

Hard start kits give compressors the extra electrical boost they need during startup, especially critical in hot weather when refrigerant pressures are high. The SPP6 includes both the start capacitor and relay needed for installation. It's designed as a universal replacement, so you'll find it works on Goodman GSX160 series, Carrier 24ABC and XC models, Trane XR15 and 4TTR series, Rheem RA and RP models, Lennox XC13 units, York LX series, and even older GE outdoor units. The kit prevents hard starting that eventually burns out compressor windings — a failure that costs $1,500+ to repair versus $20.99 for this preventive part.

Compatible Brand Coverage

This universal hard start kit works across these major HVAC brands:

• Goodman: GSX and GSZ series condensing units
• Carrier: 24ABC, XC13, and XC16 model lines
• Trane: XR15 and 4TTR residential systems
• Rheem: RA and RP series heat pumps and AC units
• Lennox: XC13 efficiency models
• York: LX Series H4H6 and similar
• GE: DTSR, DZSR, DBB, and DBXR outdoor units

Installation Overview

Turn off power at the breaker. Open the electrical access panel on your outdoor unit. The hard start kit mounts near the compressor contactor. You'll connect the start capacitor between the compressor's start and run terminals, then wire the relay according to the included diagram. Most techs complete installation in under 30 minutes. If your compressor is already struggling to start, this kit often adds years to its life — but it won't fix a compressor that's mechanically seized or has burnt windings.

When to Replace Your Hard Start Kit

Install a hard start kit if your compressor:

• Makes a grinding or buzzing sound before starting
• Trips the breaker during startup on hot days
• Takes several seconds to kick in after the thermostat calls for cooling
• Has been recommended by your HVAC tech to reduce startup stress

Hard start kits typically last 5-10 years. If yours has failed, the compressor won't start at all — you'll hear the outdoor fan running but the compressor stays silent. Replace it before the compressor itself fails from repeated hard start attempts.

Verify Your Model Number

Before ordering, confirm your outdoor unit's model number matches the compatibility list. The model number tells you the tonnage, SEER rating, and refrigerant type — all important for ensuring this universal kit will work. Most compatible models are 13-16 SEER single-stage systems from 2-5 tons. If you've got a variable-speed inverter compressor, check with your HVAC tech first — those systems use different start technology.