The Best Boiler Installers in Illinois
We graded 10 companies on seven things customers actually report: satisfaction, reliability, workmanship, value, momentum, track record and how owners handle complaints.
From 7,718 Google reviews of 10 top-rated boiler installers nationwide; 10 of them in Illinois. Updated November 11, 2026.
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Best boiler installers in Illinois for drain cleaning
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Omega Plumbing Heating and CoolingHow Job match is calculatedBuilt only from reviews Google tagged “Drain cleaning”:Stars on this job 55%4.91★Number of such jobs 25%43Overall Experts Score 20%85Job match= 90Stars are pulled toward the category average (4.92★) when a company has few tagged jobs, so 3 perfect reviews don’t beat 80 great ones. 4.3★ scores 0, 5.0★ scores full. Volume is compared with the busiest company for this job.90Job match = this company’s ★ on reviews Google tagged “Drain cleaning” (shrunk toward the category average when there are few), how many such jobs it has done, and its overall Experts Score.
What customers said about drain cleaning
Omega Plumbing Heating and CoolingMy sewer was backed up and I had water coming to the lower level of my house. I called Omega and someone was here within 20 minutes. They fixed the problem and I’m back up. Couldn’t ask for any better of service!
Omega Plumbing Heating and CoolingChris rocked! He took the time to ask questions to diagnose the issue, answered my questions and then explained what the issue was with my kitchen and washing machine drain line. He also told me how to prevent the slow drain/gargle issue I was having in my sink. Nice guy and my dog liked him too.
Omega Plumbing Heating and CoolingNick and team came out and saved the day at my house today after my basement flooded. They arrived quickly, did a comprehensive evaluation of potential causes and provided me with multiple options for solution. They looked out for me even reconnecting my dryer vent as it hadn't been fully secure, which was entirely…
Omega Plumbing Heating and CoolingBoth service people were polite and explained their work. Clearing the clogged drain was successful. They cleaned up any mess when they were finished. The only disappointment was needing to ask them to put on shoe covers inside the house.
Omega Plumbing Heating and CoolingWould definitely recommend Omega. The technician explained all of our options in terms that were easy to understand. Our new furnace and air conditioner were installed on time for the quoted price.
Omega Plumbing Heating and CoolingMajor sewer collapse at my foundation. Bob Fox and his crew of plumbers had it fixed in a few hours. They had to dig out my foundation, repair the collapsed cast iron sewer and all the related pvc in the house They put runners down everywhere in the house... Left everything spotless.. I thought my yard would be…
Overall ratings
Experts Score 0–100Experts Score (0–100)Absolute quality first: recency-weighted star average (≈54%), share of 1–2★ reviews (≈24%), customers’ price verdicts (≈14%), owner replies to critical reviews (≈7%); minus up to 10 points each for complaints flagged in Google review highlights and for a real slide in recent ratings. Hover a company’s score on its page for the full breakdown. and a letter grade per factor (A = top 20% of boiler installers).
| # | Company | ScoreExperts Score (0–100)Absolute quality first: recency-weighted star average (≈54%), share of 1–2★ reviews (≈24%), customers’ price verdicts (≈14%), owner replies to critical reviews (≈7%); minus up to 10 points each for complaints flagged in Google review highlights and for a real slide in recent ratings. Hover a company’s score on its page for the full breakdown. | FactorsFactor grades, in orderSatisfaction (54%): Recency-weighted star average (2-year half-life), shrunk toward the category mean by review volume; the company’s own lifetime average as the prior; absolute: 4.0★ = 0, 5★ = 100.Reliability (24%): How rarely jobs go badly: share of 1–2★ reviews — 60% the last 24 months (or the 20 newest if fewer), 40% all-time; 0% = 100, 15%+ = 0; the category percentile can only raise it.Craft & service (0%): Google review highlights: Quality, Professionalism, Responsiveness, Punctuality — how rarely reviewers flag them as a negative, per review since highlights began; 0% = 100, 5%+ = 0. Subtracted from the score (up to −10), never averaged in — clean highlights are the norm, not a bonus.Value (14%): Customers’ own price verdicts (Great / Reasonable vs Overpriced) and Value highlights; 65% absolute (all “reasonable” ≈ 80, “great” = 100), the category percentile can only raise it.Momentum (0%): Penalises only a real slide: last-12-month average below lifetime (−0.5★ = 0). Still 4.8★+ over the last year, or steady/improving = 100. Subtracted from the score (up to −10), never averaged in.Replies to reviews (7%): How often the owner publicly replies to reviews under 5★ (1–4★). Needs 3+ such reviews, otherwise not counted; 65% absolute (80%+ replied = 100), the category percentile can only raise it.One letter per factor score: A = 80+, B = 60–79, C = 40–59, D = 20–39, F = below 20. | ★Google star rating as shown on Google Maps. | Typical billMedian bill customers of this company reported in their reviews (needs 3+ priced reviews). |
|---|---|---|---|---|---|
| 1 |  Windy City HVAC RepairJoliet, IL | A 99How the Experts Score is calculatedEach factor is scored 0–100 on absolute terms (standing in the category can only raise it), then weighted; problems flagged in review highlights or a recent slide in ratings are subtracted:Satisfaction 59%99+58.1Reliability 26%99+25.8Value 15%100+15.2Experts Score= 99Not enough data for replies to reviews; its weight is shared by the others.Grade A: A = 80+, B = 60–79, C = 40–59, D = 20–39. Needs 10+ reviews. | AA–AA– | 4.99 | $166 |
| 2 |  Zark Heating & Cooling Inc.Joliet, IL | A 97How the Experts Score is calculatedEach factor is scored 0–100 on absolute terms (standing in the category can only raise it), then weighted; problems flagged in review highlights or a recent slide in ratings are subtracted:Satisfaction 55%97+52.9Reliability 24%96+23.3Value 14%100+14.1Replies to reviews 7%100+7.1Experts Score= 97Grade A: A = 80+, B = 60–79, C = 40–59, D = 20–39. Needs 10+ reviews. | AAAAAA | 4.97 | $227 |
| 3 |  Rousculp's Heating and CoolingJoliet, IL | A 96How the Experts Score is calculatedEach factor is scored 0–100 on absolute terms (standing in the category can only raise it), then weighted; problems flagged in review highlights or a recent slide in ratings are subtracted:Satisfaction 55%99+54Reliability 24%99+24Value 14%100+14.1Replies to reviews 7%58+4.1Experts Score= 96Grade A: A = 80+, B = 60–79, C = 40–59, D = 20–39. Needs 10+ reviews. | AAAAAC | 4.98 | $161 |
| 4 |  Comfort Zone ServiceJoliet, IL | A 96How the Experts Score is calculatedEach factor is scored 0–100 on absolute terms (standing in the category can only raise it), then weighted; problems flagged in review highlights or a recent slide in ratings are subtracted:Satisfaction 55%95+51.8Reliability 24%93+22.5Value 14%100+14.1Replies to reviews 7%100+7.1Experts Score= 96Grade A: A = 80+, B = 60–79, C = 40–59, D = 20–39. Needs 10+ reviews. | AAAAAA | 4.96 | $248 |
| 5 |  Service Express Heating and Air ConditioningJoliet, IL | A 96How the Experts Score is calculatedEach factor is scored 0–100 on absolute terms (standing in the category can only raise it), then weighted; problems flagged in review highlights or a recent slide in ratings are subtracted:Satisfaction 55%95+51.8Reliability 24%94+22.8Value 14%100+14.1Replies to reviews 7%100+7.1Experts Score= 96Grade A: A = 80+, B = 60–79, C = 40–59, D = 20–39. Needs 10+ reviews. | AAAAAA | 4.94 | $228 |
| 6 |  Deljo Heating, Cooling & PlumbingJoliet, IL | A 95How the Experts Score is calculatedEach factor is scored 0–100 on absolute terms (standing in the category can only raise it), then weighted; problems flagged in review highlights or a recent slide in ratings are subtracted:Satisfaction 55%95+51.8Reliability 24%97+23.5Value 14%88+12.4Replies to reviews 7%100+7.1Experts Score= 95Grade A: A = 80+, B = 60–79, C = 40–59, D = 20–39. Needs 10+ reviews. | AA–AAA | 4.95 | $383 |
| 7 |  Maertin Heating & CoolingJoliet, IL | A 93How the Experts Score is calculatedEach factor is scored 0–100 on absolute terms (standing in the category can only raise it), then weighted; problems flagged in review highlights or a recent slide in ratings are subtracted:Satisfaction 55%96+52.4Reliability 24%94+22.8Value 14%100+14.1Replies to reviews 7%58+4.1Experts Score= 93Grade A: A = 80+, B = 60–79, C = 40–59, D = 20–39. Needs 10+ reviews. | AAAAAC | 4.98 | $423 |
| 8 |  Service 1 Plumbing, Heating & A/C, Inc.Joliet, IL | A 91How the Experts Score is calculatedEach factor is scored 0–100 on absolute terms (standing in the category can only raise it), then weighted; problems flagged in review highlights or a recent slide in ratings are subtracted:Satisfaction 55%92+50.2Reliability 24%91+22.1Value 14%100+14.1Replies to reviews 7%67+4.7Craft & service penalty98−0.2Experts Score= 91Grade A: A = 80+, B = 60–79, C = 40–59, D = 20–39. Needs 10+ reviews. | AAAAAB | 4.90 | $283 |
| 9 |  Energy Services Air Conditioning & Heating Co. & ElectricalJoliet, IL | A 85How the Experts Score is calculatedEach factor is scored 0–100 on absolute terms (standing in the category can only raise it), then weighted; problems flagged in review highlights or a recent slide in ratings are subtracted:Satisfaction 55%86+46.9Reliability 24%85+20.6Value 14%97+13.7Replies to reviews 7%59+4.2Craft & service penalty99−0.1Experts Score= 85Grade A: A = 80+, B = 60–79, C = 40–59, D = 20–39. Needs 10+ reviews. | AAAAAC | 4.89 | $166 |
| 10 | Omega Plumbing Heating and CoolingJoliet, IL | A 85How the Experts Score is calculatedEach factor is scored 0–100 on absolute terms (standing in the category can only raise it), then weighted; problems flagged in review highlights or a recent slide in ratings are subtracted:Satisfaction 55%89+48.5Reliability 24%85+20.6Value 14%89+12.6Replies to reviews 7%60+4.2Craft & service penalty87−1.3Experts Score= 85Grade A: A = 80+, B = 60–79, C = 40–59, D = 20–39. Needs 10+ reviews. | AAAAAB | 4.87 | $383 |
What jobs cost
What customers paid, from the price Google asks reviewers to report.
| Job | Low25th percentile: 1 in 4 customers paid less than this. | TypicalMedian of the bill customers reported in their Google review (Google asks reviewers for a price range; we use the middle of each range). | High75th percentile: 1 in 4 customers paid more than this. | FairOf customers who rated the price, the share who chose “Great price” or “Reasonable” rather than “Overpriced”. |
|---|---|---|---|---|
| HVAC system maintenance | $37 | $124 | $264 | 99% |
| A/C system maintenance | $39 | $166 | $318 | 99% |
| HVAC system repair | $145 | $325 | $618 | 98% |
| Heating system maintenance | $37 | $161 | $317 | 98% |
| Heating system installation | $1.4k | $2.1k | $2.8k | 99% |
| Heating system repair | $78 | $192 | $745 | 98% |
| A/C system repair | $216 | $322 | $611 | 98% |
| Install AC | $1.6k | $2.4k | $3.2k | 100% |
| Cleaning | $135 | $198 | $484 | 100% |
| Plumbing pipe repair | $251 | $399 | $480 | 94% |
| Toilet repair | $246 | $340 | $496 | 97% |
| Water heater installation | $1.1k | $1.4k | $2.1k | 100% |
Boiler Installers in Illinois at a glance
How the 10 boiler installers we rated in Illinois compare, and what customers praise most.
Experts Score grades
A = score 80+, F = below 20.
- Grade A10100%
- Grade B00%
- Grade C00%
- Grade D00%
- Grade F00%
Google ratings
Average stars per company.
- 4.90★ and up880%
- 4.80–4.89★220%
- 4.60–4.79★00%
- Below 4.60★00%
What customers praise
Share of Google review highlights.
- Quality1,32320%
- Professionalism1,50923%
- Responsiveness1,36921%
- Punctuality1,32920%
- Value1,04916%
Was the price fair?
All price verdicts left with reviews.
- Great price52829%
- Reasonable1,15363%
- Overpriced332%
- Not sure1136%
Price verdicts by year
Share calling it great / reasonable / overpriced.
How we grade
Satisfaction (54%) — Recency-weighted star average (2-year half-life), shrunk toward the category mean by review volume; the company’s own lifetime average as the prior; absolute: 4.0★ = 0, 5★ = 100.
Reliability (24%) — How rarely jobs go badly: share of 1–2★ reviews — 60% the last 24 months (or the 20 newest if fewer), 40% all-time; 0% = 100, 15%+ = 0; the category percentile can only raise it.
Craft & service (penalty, up to −10) — Google review highlights: Quality, Professionalism, Responsiveness, Punctuality — how rarely reviewers flag them as a negative, per review since highlights began; 0% = 100, 5%+ = 0. Subtracted from the score (up to −10), never averaged in — clean highlights are the norm, not a bonus.
Value (14%) — Customers’ own price verdicts (Great / Reasonable vs Overpriced) and Value highlights; 65% absolute (all “reasonable” ≈ 80, “great” = 100), the category percentile can only raise it.
Momentum (penalty, up to −10) — Penalises only a real slide: last-12-month average below lifetime (−0.5★ = 0). Still 4.8★+ over the last year, or steady/improving = 100. Subtracted from the score (up to −10), never averaged in.
Replies to reviews (7%) — How often the owner publicly replies to reviews under 5★ (1–4★). Needs 3+ such reviews, otherwise not counted; 65% absolute (80%+ replied = 100), the category percentile can only raise it.