The Best Boiler Installers in Illinois

Find the right company for your job

Pick the job — we re-rank companies by how customers rated that exact job.

1Service Express Heating and Air Conditioning★ 4.97 on this job67 jobs reviewedusually $200–400iHow Job match is calculatedBuilt only from reviews Google tagged “A/C system repair”:Stars on this job 55%4.97★Number of such jobs 25%67Overall Experts Score 20%96Job match= 96Stars 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.96

2Maertin Heating & Cooling★ 5.00 on this job26 jobs reviewedusually $400–600iHow Job match is calculatedBuilt only from reviews Google tagged “A/C system repair”:Stars on this job 55%5.00★Number of such jobs 25%26Overall Experts Score 20%93Job match= 92Stars 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.92

3Deljo Heating, Cooling & Plumbing★ 5.00 on this job21 jobs reviewedusually $2,000+iHow Job match is calculatedBuilt only from reviews Google tagged “A/C system repair”:Stars on this job 55%5.00★Number of such jobs 25%21Overall Experts Score 20%95Job match= 91Stars 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.91

4Service 1 Plumbing, Heating & A/C, Inc.★ 4.97 on this job33 jobs reviewediHow Job match is calculatedBuilt only from reviews Google tagged “A/C system repair”:Stars on this job 55%4.97★Number of such jobs 25%33Overall Experts Score 20%91Job match= 91Stars 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.91

5Comfort Zone Service★ 5.00 on this job17 jobs reviewedusually $800–1,000iHow Job match is calculatedBuilt only from reviews Google tagged “A/C system repair”:Stars on this job 55%5.00★Number of such jobs 25%17Overall Experts Score 20%96Job match= 89Stars 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.89

6Energy Services Air Conditioning & Heating Co. & Electrical★ 4.95 on this job39 jobs reviewedusually $1–200iHow Job match is calculatedBuilt only from reviews Google tagged “A/C system repair”:Stars on this job 55%4.95★Number of such jobs 25%39Overall Experts Score 20%85Job match= 89Stars 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.89

7Rousculp's Heating and Cooling★ 5.00 on this job14 jobs reviewedusually $2,000+iHow Job match is calculatedBuilt only from reviews Google tagged “A/C system repair”:Stars on this job 55%5.00★Number of such jobs 25%14Overall Experts Score 20%96Job match= 88Stars 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.88

8Zark Heating & Cooling Inc.★ 4.82 on this job45 jobs reviewedusually $200–400iHow Job match is calculatedBuilt only from reviews Google tagged “A/C system repair”:Stars on this job 55%4.82★Number of such jobs 25%45Overall Experts Score 20%97Job match= 84Stars 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.84

Job match = this company’s ★ on reviews Google tagged “A/C system 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 a/c system repair

John8 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 days ago★★★★★

Service Express Heating and Air C…

Service Express has serviced our HVAC units for over 20 years. Not only have I been impressed with the level of service over this time frame, but every technician who has come into my home has been professional, courteous, and comfortable to be around. Thank you.

HVAC system repairA/C system repairInstall AC

Wendy1 reviewiTotal 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. · 3 weeks ago★★★★★

Deljo Heating, Cooling & Plumbing

George & Deljo are great! We’ve been clients of theirs for over 10 years. Never had a complaint. They are always prompt, professional, and honest. Don’t be fooled by the places that have flashy ads on local television. You won’t be disappointed with Deljo!

Paid $2,000+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

Steven9 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★★★★★

Energy Services Air Conditioning …

Highly recommend Energy Services Air Conditioning & Heating. They are thorough, knowledgeable, insightful and, most importantly, trustworthy. They stood behind their previous work and made sure everything was right, which says a lot about the company and how they treat their customers. Andrew and Mohammed were both… Read full review

Great priceHVAC system repairA/C system repairThermostat repair

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

EmilyLocal Guide · 80 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★★★★★

Maertin Heating & Cooling

The air went out today on the hottest day so far this summer - early fall. We contacted Maertin to do a service call. Thankfully, the tech, Michael got us back up and running! He explained what was needed and was very pleasant and professional. Thank you!!!

Paid $600–800Reasonable priceA/C system 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.