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5-2-1 Compressor Saver Hard Start Kit CSR-U2 2 to 3.5 Ton Units
National HVAC Parts

5-2-1 Compressor Saver Hard Start Kit CSR-U2 2 to 3.5 Ton Units

SKU: NHVAC-HARD-3N44Z5 Brand: National HVAC Parts
$32.00 $43.20

Order before 3PM CST — ships same day.
Standard delivery 2-5 business days. Express options at checkout.

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5-2-1 Compressor Saver Hard Start Kit CSR-U2 2 to 3.5 Ton Units

A plug-and-play compressor hard start kit for 2 to 3.5 ton residential AC units and heat pumps. Installs in minutes with no wiring changes and immediately improves compressor starting reliability, especially in hot weather or when voltage sags during peak demand.

Key Features

  • Fits 2 to 3.5 ton compressors — covers most residential AC systems
  • Reduces startup current draw by up to 50%
  • Plug-and-play installation — connect 2 wires, done
  • Extends compressor life by reducing mechanical startup stress

Specifications

  • Tonnage: 2 to 3.5 tons
  • Voltage: 187-264 VAC
  • Connection: Push-on terminals

What's Included

  • Hard start kit
  • Installation guide

Ships same-day from our Houston warehouse on orders placed before 3PM CST.

Frequently Asked Questions

Will this help my AC start in extreme heat?

Yes, this is exactly what a hard start kit is designed for. In extreme heat, refrigerant pressures are higher, making the compressor work harder to start. The hard start kit provides the extra torque needed.

My AC is only 2 years old. Does it still need a hard start kit?

Even new systems benefit from a hard start kit, especially if you have a long lineset (over 50 feet), are in a hot climate, or have experienced voltage issues. It is inexpensive compressor insurance.

Can I install this myself?

Yes, if you are comfortable working around electrical components. Turn off power at the disconnect, connect two wires to the contactor, and restore power. However, if unsure, hire a licensed technician.

Does this work with heat pumps?

Yes, it works with both AC and heat pump compressors in the 2 to 3.5 ton range.

Shipping Information

  • Orders placed before 3PM CST ship same business day
  • Standard delivery: 2-5 business days
  • Express shipping available at checkout
  • Free shipping on orders over $75
  • Tracking number emailed upon shipment

Return Policy

  • 30-day returns on unused parts in original packaging
  • Electrical parts (capacitors, contactors, control boards) are final sale once installed
  • Email support@nationalhvacparts.com to initiate a return
  • Refunds processed within 5-7 business days

Frequently Asked Questions

Does this Hard Start Kits & Compressor Accessories fit my National HVAC Parts 5-2-1 Compressor Saver Hard Start Kit CSR-U2 2 to 3.5 Ton Units?
Yes. This is the factory-specified OEM hard start kits & compressor accessories for the National HVAC Parts 5-2-1 Compressor Saver Hard Start Kit CSR-U2 2 to 3.5 Ton Units. It is a direct drop-in replacement that fits without modification. Always verify the model number on your equipment nameplate before ordering.
How do I replace the hard start kits & compressor accessories on my National HVAC Parts 5-2-1 Compressor Saver Hard Start Kit CSR-U2 2 to 3.5 Ton Units?
Refer to your equipment service manual for model-specific steps. General approach: turn off power, photograph connections, remove old part, install new part, restore power and test. For gas components, hire a licensed technician. Email info@nationalhvacparts.com for guidance.
What symptoms mean I need a new hard start kits & compressor accessories?
Common symptoms: unusual noises, intermittent operation, complete failure, or visible damage. Visit our diagnostic hub for symptom-based troubleshooting.
Is this hard start kits & compressor accessories compatible with Bryant or Payne too?
Many National HVAC Parts parts are cross-compatible with Bryant and Payne since all three brands are manufactured by Carrier Global Corporation. The same physical part is often used across brand labels with different model numbers. To verify: check your Bryant or Payne equipment service manual for cross-compatible part numbers, or email info@nationalhvacparts.com with your model number.
Should I use OEM or aftermarket for my National HVAC Parts hard start kits & compressor accessories?
OEM recommended for reliability and warranty compatibility. OEM parts match exact factory specifications for proper fit, performance, and safety. While aftermarket alternatives cost less upfront, the risk of improper fit and reduced lifespan usually makes OEM the better value long-term.
How fast does National HVAC Parts ship?
Orders placed before 3:00 PM CST ship the same business day. Standard delivery is 2–5 business days anywhere in the continental United States. Express shipping available at checkout. We ship from Houston, TX to all 50 states. 30-day return policy on all parts.
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