Frequently Asked Questions

  • What's the difference between a 13 SEER and 20 SEER air conditioner?

    SEER measures cooling efficiency—higher numbers mean lower electric bills. A 13 SEER is the minimum efficiency standard and works well for budget-conscious homeowners, while an 20 SEER can cut cooling costs by 20–30% over time. At Gilley's Heating & Air, we perform load calculations to match the right SEER rating to your Rockford home's size and usage patterns.

  • How often should you schedule furnace maintenance in northern Illinois?

    Annual furnace maintenance is essential before heating season, typically in late summer or early fall. Regular tune-ups catch small issues before they become costly winter breakdowns and keep your system running safely and efficiently. Gilley's Comfort Club members receive bi-annual system checks, including fall furnace inspections tailored to Illinois winters.

  • What affects the cost of AC replacement in Rockford?

    AC replacement cost depends on system size, SEER rating, brand choice, ductwork condition, and installation complexity. Premium brands like American Standard cost more upfront but offer longer warranties and quieter operation. At Gilley's, we provide free home assessments with load calculations to ensure proper sizing and transparent pricing with no hidden fees.

  • Can a furnace that's too big waste energy?

    Yes—an oversized furnace short-cycles, turning on and off frequently, which wastes fuel and wears out components faster. Proper sizing requires a load calculation based on your home's insulation, windows, and layout, not just square footage. Gilley's guarantees correct sizing on every heating installation to maximize efficiency and comfort.

  • How does a tankless water heater work differently than a tank model?

    Tankless water heaters heat water on demand as it flows through the unit, eliminating standby energy loss from keeping a tank hot 24/7. They provide endless hot water and last 20+ years versus 10–15 for tanks. At Gilley's, we help Rockford homeowners choose between tank and tankless based on household size, usage patterns, and budget.

  • What's the biggest mistake people make with AC systems?

    Skipping annual maintenance is the most common mistake—it leads to reduced efficiency, higher energy bills, and unexpected breakdowns during summer heat. Dirty coils and clogged filters force your AC to work harder and fail sooner. Gilley's recommends spring tune-ups every year to keep your cooling system running reliably through hot Illinois summers.

  • Why does my toilet keep running after I flush it?

    A running toilet usually means a worn flapper valve, faulty fill valve, or misadjusted float inside the tank. This wastes hundreds of gallons of water monthly and drives up your bill. Gilley's licensed plumbers can diagnose and repair toilet issues quickly, often with same-day service across Rockford and surrounding communities.

  • Do UV lights in HVAC systems actually kill mold and bacteria?

    Yes, UV-C light installed in your ductwork destroys mold spores, bacteria, and viruses as air circulates through your system. It's especially helpful for homes with allergies, asthma, or musty odors. At Gilley's, we install UV air purification systems as part of our indoor air quality solutions for healthier Rockford homes.

  • How long does a typical furnace last in Illinois?

    Most furnaces last 15–20 years with proper maintenance, though harsh Illinois winters can shorten lifespan if the system is undersized or poorly maintained. Signs it's time to replace include frequent repairs, rising energy bills, and uneven heating. Gilley's offers free home assessments and 10-year manufacturer warranties on all new heating installations.

  • What causes low water pressure throughout the house?

    Low water pressure often results from sediment buildup in pipes, a failing pressure regulator, hidden leaks, or corroded plumbing. Whole-house pressure issues require professional diagnosis to identify the root cause. Gilley's licensed plumbers inspect water pressure, flow rates, and pipe condition to restore proper performance across your Rockford home.

  • Is a heat pump effective in cold Rockford winters?

    Modern cold-climate heat pumps work efficiently down to -15°F, but traditional models lose heating capacity below 30°F and require backup heat. Rockford's winter lows make dual-fuel systems (heat pump plus gas furnace) a smart choice for efficiency and reliability. At Gilley's, we recommend heating solutions based on your home's needs and Illinois weather patterns.

  • How do you prepare your plumbing for a freezing Illinois winter?

    Insulate exposed pipes, disconnect outdoor hoses, drain sprinkler systems, and seal crawl space vents to prevent freeze damage. Let faucets drip during extreme cold to keep water moving. Gilley's plumbers offer whole-home plumbing inspections each fall to identify vulnerabilities before temperatures drop across Belvidere and Rockford.