The Best Boiler Installers in Illinois

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1Service 1 Plumbing, Heating & A/C, Inc.★ 5.00 on this job9 jobs reviewediHow Job match is calculatedBuilt only from reviews Google tagged “HVAC duct & vent repair”:Stars on this job 55%5.00★Number of such jobs 25%9Overall Experts Score 20%91Job match= 95Stars 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.95

2Zark Heating & Cooling Inc.★ 5.00 on this job7 jobs reviewedusually $400–600iHow Job match is calculatedBuilt only from reviews Google tagged “HVAC duct & vent repair”:Stars on this job 55%5.00★Number of such jobs 25%7Overall Experts Score 20%97Job match= 94Stars 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.94

3Service Express Heating and Air Conditioning★ 5.00 on this job7 jobs reviewediHow Job match is calculatedBuilt only from reviews Google tagged “HVAC duct & vent repair”:Stars on this job 55%5.00★Number of such jobs 25%7Overall Experts Score 20%96Job match= 93Stars 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.93

4Rousculp's Heating and Cooling★ 5.00 on this job5 jobs reviewedusually $100–200iHow Job match is calculatedBuilt only from reviews Google tagged “HVAC duct & vent repair”:Stars on this job 55%5.00★Number of such jobs 25%5Overall Experts Score 20%96Job 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.90

5Maertin Heating & Cooling★ 5.00 on this job4 jobs reviewedusually $1,000+iHow Job match is calculatedBuilt only from reviews Google tagged “HVAC duct & vent repair”:Stars on this job 55%5.00★Number of such jobs 25%4Overall Experts Score 20%93Job match= 87Stars 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.87

6Comfort Zone Service★ 5.00 on this job4 jobs reviewedusually $1–100iHow Job match is calculatedBuilt only from reviews Google tagged “HVAC duct & vent repair”:Stars on this job 55%5.00★Number of such jobs 25%4Overall Experts Score 20%96Job match= 87Stars 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.87

7Energy Services Air Conditioning & Heating Co. & Electrical★ 5.00 on this job3 jobs reviewediHow Job match is calculatedBuilt only from reviews Google tagged “HVAC duct & vent repair”:Stars on this job 55%5.00★Number of such jobs 25%3Overall Experts Score 20%85Job match= 82Stars 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.82

Job match = this company’s ★ on reviews Google tagged “HVAC duct & vent repair” (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 HVAC duct & vent repair

Malgorzata2 reviewsiTotal number of Google reviews this person has written across all businesses on Google Maps (not just this one). More reviews usually means a more experienced, trustworthy reviewer. · Edited 3 weeks ago★★★★★

Service Express Heating and Air C…

For the third year, we have maintained contracts with this company for large commercial campuses operating seven days a week. We are very satisfied with the professionalism they demonstrate in every aspect of their services.

Great priceHVAC system repairHVAC system maintenanceA/C system maintenance

MichaelLocal Guide · 59 reviewsiTotal number of Google reviews this person has written across all businesses on Google Maps (not just this one). More reviews usually means a more experienced, trustworthy reviewer. · Edited 2 months ago★★★★★

Zark Heating & Cooling Inc.

Honest and professional work! They've done a water heater replacement, AC repair, and furnace maintenance for us. Can't recommend them enough! Same great service on 9/10/26, they were able to get our shop AC up and running quickly! Bill was knowledgeable and through. Excellent job again.

Paid $400–600Great priceA/C system maintenanceDuctless heating & A/C servicesHeating system maintenance+ Responsiveness+ Punctuality+ Professionalism

RandyLocal Guide · 51 reviewsiTotal number of Google reviews this person has written across all businesses on Google Maps (not just this one). More reviews usually means a more experienced, trustworthy reviewer. · Edited 2 months ago★★★★★

Service 1 Plumbing, Heating & A/C…

Service One installed my system 11 years ago and has taken great care of it ever since. I would not go with anyone else. All of the technicians that have come out have been polite, courteous, and professional. 9/5/26: John came out to replace a capacitor and some wiring due to a hungry mouse who had its last meal. Work was completed efficiently.

HVAC system maintenanceA/C system maintenanceHeating system repair+ Responsiveness+ Punctuality+ Quality

Mark4 reviewsiTotal number of Google reviews this person has written across all businesses on Google Maps (not just this one). More reviews usually means a more experienced, trustworthy reviewer. · 2 months ago★★★★★

Rousculp's Heating and Cooling

Rousculp's followed through with the job I needed to have done. They were timely, professional and took the time to explain things I did not fully understand. I would recommend them to friends and family.

Paid $800–1,000Not sureHVAC duct & vent repair

Andrew4 reviewsiTotal number of Google reviews this person has written across all businesses on Google Maps (not just this one). More reviews usually means a more experienced, trustworthy reviewer. · Edited 6 months ago★★★★★

Comfort Zone Service

Confort Zone is amazing, they do amazing work at a very fair price. The team is respectful and responsive. Would recommend them to anyone

HVAC system maintenanceHVAC system repairHVAC duct & vent repair+ Responsiveness+ Punctuality+ Quality

Carl3 reviewsiTotal number of Google reviews this person has written across all businesses on Google Maps (not just this one). More reviews usually means a more experienced, trustworthy reviewer. · 9 months ago★★★★★

Maertin Heating & Cooling

Called Martin Heating and Cooling for service and as always prompt service. They are great. Scott and his team are very trustworthy and knowledgeable. We have been working with them for as far as I can remember (years) and do not ever think to call anyone else with HVAC issues. Ended up replacing both furnaces… Read full review

Paid $1,000+Great priceHVAC system maintenanceHeating system repairHVAC duct & vent repair

Overall ratings

Experts Score 0–100iExperts 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	ScoreiExperts 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.	FactorsiFactor 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.	★iGoogle star rating as shown on Google Maps.	Typical billiMedian bill customers of this company reported in their reviews (needs 3+ priced reviews).
1	Windy City HVAC RepairJoliet, IL	A 99iHow 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 97iHow 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 96iHow 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 96iHow 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 96iHow 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 95iHow 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 93iHow 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 91iHow 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 85iHow 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 85iHow 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.

Boiler Installers in Illinois at a glance

How the 10 boiler installers we rated in Illinois compare, and what customers praise most.

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.