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By CR Score, the highest-ranked HVAC contractor in Waukegan, IL is Cahill Heating, Cooling, Electric, Plumbing & Sewer with a CR Score of 63/100. It has 5.0★ from 1,064 Google reviews. It is open 24/7. Herchenbach Mechanical Inc. (#2) and TopTec Heating, Cooling, Plumbing & Electrical (#3) follow. We ranked 613 HVAC contractors on ten factors, last updated October 22, 2026.
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ContractorsRanked ranks 613 HVAC contractors serving Waukegan, IL. 2 of them are based in Waukegan; the rest serve it from nearby towns. Another 20 within 25 mi are listed but not ranked yet. Counts are as of October 2026.
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273 ranked HVAC contractors in Waukegan post 24/7 hours. The highest-ranked are Cahill Heating, Cooling, Electric, Plumbing & Sewer (#1), Herchenbach Mechanical Inc. (#2) and TopTec Heating, Cooling, Plumbing & Electrical (#3). Hours come from each business's Google listing as of October 2026, so call to confirm.
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467 of 613 ranked HVAC contractors post Saturday hours and 380 post Sunday hours. The highest-ranked open Saturdays are Cahill Heating, Cooling, Electric, Plumbing & Sewer (#1), Herchenbach Mechanical Inc. (#2) and TopTec Heating, Cooling, Plumbing & Electrical (#3). Posted hours are office hours; crews may book weekend jobs separately.
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AC replacement typically costs $3,887 to $8,073, with $5,978 typical (Per system, installed (unit plus labor); typical range of customer-reported jobs. US national range). This is a national range, not adjusted for Waukegan. Prices were last checked October 2026. Get at least two written quotes before you hire.
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The median Google rating among 613 rated HVAC contractors in Waukegan is 4.9★, with a median of 24 reviews. ABC Plumbing, Sewer, Heating, Cooling & Electric has the most, 22,524 reviews, and ranks #4. We adjust ratings for review count, so a few five-star reviews cannot top the list.
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In Illinois, furnace and heat pump calls peak in the coldest winter weeks and AC calls in summer heat waves. Spring and fall are the easiest times to book maintenance or a replacement.
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Each HVAC contractor gets a 0–100 CR Score from ten published factors, led by reputation (25%), credentials (15%), review volume (10%) and trade focus (10%). A business with no Google reviews scores zero on rating, review volume and recency; other factors we cannot measure are left out. Only businesses with a confirmed trade and 3 or more reviews, or a claimed profile, are ranked.