AC Replacment

Reliable Residential AC Replacement for Illinois Homes

When your air conditioner is aging, inefficient, or frequently breaking down, it may be time for a replacement. Gilley’s Heating & Air Conditioning provides expert AC replacement services across Rockford, Loves Park, Machesney Park, and surrounding Northern Illinois communities.


Our licensed, EPA-certified technicians install American Standard high-efficiency systems to ensure your home stays cool, comfortable, and energy-efficient. Call us at (815) 962-1927 to schedule today.

HVAC technician showing a tablet to a couple next to an air conditioning unit outside a brick house.
American Standard air conditioner ad. Text says

Signs It’s Time to Replace Your Air Conditioner

Homeowners often wait too long, risking high repair costs and inefficient cooling. Consider AC replacement if:


  • Your system is over 12 years old
  • It frequently breaks down or requires major repairs
  • Cooling is uneven across rooms
  • Energy bills are rising despite normal use
  • The system uses outdated refrigerants like R-22
  • Your AC cannot maintain desired indoor comfort


A modern, high-efficiency system provides reliable cooling, lower energy costs, and improved indoor air quality for your home.

Top Brands & High-Efficiency Options

Gilley’s is a factory-certified dealer for American Standard. We install energy-efficient systems with the latest technology, including variable-speed blowers, smart thermostats, and advanced refrigerants. Our team ensures the new unit is properly sized using load calculations, so your Rockford home receives optimal cooling without oversizing or inefficiency.

Our AC Replacement Process

  1. Schedule Your Consultation: Call (815) 962-1927 or request a service via email. Same-day appointments are often available for many Rockford homes.
  2. Home Assessment & Recommendations: Our technicians evaluate your current system, ductwork, insulation, and cooling needs. We provide options for high-efficiency units and explain manufacturer warranties.
  3. Professional Installation: We install your new AC system with care, handling electrical connections, refrigerant lines, and thermostat setup.
  4. System Testing & Verification: After installation, we run multiple cooling cycles, check airflow, verify thermostat accuracy, and ensure your system operates safely and efficiently.


All installations are backed by manufacturer warranties and Gilley’s 1-year labor guarantee for peace of mind.

Why Hire Gilley’s for AC Replacement in Rockford, IL and surrounding areas

Family-owned since 1985, Gilley’s provides fast, reliable AC replacement with licensed, EPA-certified technicians and a 1-year labor warranty.

  • Trusted Experience: 40+ years serving Rockford, Loves Park, Machesney Park, and surrounding areas.
  • Top Brands & High-Efficiency Systems: American Standard with proper sizing and installation.
  • Rebates & Financing: Assistance with tax credits (when available), utility rebates, manufacturer promotions, and flexible financing.
  • Proven Track Record: Thousands of successful installations delivering reliable, energy-efficient cooling for Northern Illinois homes.

Schedule Your AC Replacement Today

Don’t wait for another breakdown. Call (815) 962-1927 or request a service from our contact page to schedule your professional AC replacement in Rockford, Loves Park, Machesney Park, and surrounding areas. Trust Gilley’s Heating & Air Conditioning to keep your home cool and energy-efficient all summer long.

Frequently Asked Questions

  • When should I replace my AC instead of repairing it?

    Generally, replace your AC if it's 12+ years old, requires repairs exceeding $1,000, uses R-22 refrigerant (being phased out at $150-$300 per pound), or you've had 3+ repairs in the past 2 years. The 50% rule helps: if repair costs exceed 50% of replacement cost AND your AC is over 10 years old, replacement offers better long-term value. We'll walk you through the cost-benefit analysis honestly, never pressuring you toward unnecessary replacement.

  • How much does AC replacement cost in Rockford?

    Complete AC replacement in Rockford typically costs $4,500-$8,500 depending on system size and efficiency. Most homeowners invest $5,500-$6,500 for mid-efficiency (13-15 SEER) systems that balance upfront cost with long-term energy savings. We provide free estimates with multiple options at different price points, plus help you access available rebates that reduce your net cost.

  • How long does AC replacement take?

    Most AC replacements take 6-10 hours and are completed in a single day when existing ductwork is in good condition. Installation can extend to 1-2 days if you need ductwork modifications, electrical service upgrades, refrigerant line replacement, or smart thermostat installation with advanced programming. We provide an accurate timeline after assessing your specific situation during the free estimate.

  • What size AC do I need for my home?

    AC size depends on square footage, insulation quality, window count and type, ceiling height, and ductwork condition. We perform load calculations to size your system correctly—not rough square footage estimates. General guidelines: 1,000-1,400 sq ft homes need 2-2.5 ton; 1,800-2,400 sq ft need 3-4 ton; 2,400-3,000 sq ft need 4-5 ton. Proper sizing prevents short-cycling, ensures dehumidification, and maximizes efficiency.

  • Can I replace just the outdoor unit?

    We don't recommend replacing only the outdoor unit. Modern AC systems are designed as matched sets—outdoor unit and indoor coil engineered to work together for optimal efficiency and reliability. Mismatched components void manufacturer warranties, reduce efficiency by 15-25%, and often fail prematurely. If your indoor coil is 10+ years old, replacing both components together ensures proper operation and full warranty coverage.

  • Do you offer financing for AC replacement?

    Yes, we offer flexible financing with approved credit including various terms and payment plans to fit your budget. Financing makes high-efficiency systems affordable by spreading costs over time while you immediately enjoy lower energy bills. We'll explain all available options during your free estimate.

  • Are high-efficiency AC systems worth it in Rockford?

    Yes, high-efficiency AC systems (18+ SEER) are worth the investment in Rockford. They use 20-40% less electricity, provide better dehumidification during humid summers, run quieter with variable-speed technology, and qualify for energy rebates. Most homeowners recover the additional upfront cost in 8-12 years through energy savings. Over the system's 15-year lifespan, high-efficiency models save thousands in cooling costs.