The Best Boiler Installers
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. Updated November 11, 2026.
Find the right company for your job
Pick the job — we re-rank companies by how customers rated that exact job.
Best boiler installers for cleaning
Clear ✕
Service Express Heating and Air ConditioningHow Job match is calculatedBuilt only from reviews Google tagged “Cleaning”:Stars on this job 55%5.00★Number of such jobs 25%89Overall Experts Score 20%96Job match= 99Stars 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.99
Energy Services Air Conditioning & Heating Co. & ElectricalHow Job match is calculatedBuilt only from reviews Google tagged “Cleaning”:Stars on this job 55%4.95★Number of such jobs 25%56Overall 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.90
Comfort Zone ServiceHow Job match is calculatedBuilt only from reviews Google tagged “Cleaning”:Stars on this job 55%5.00★Number of such jobs 25%17Overall 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
Deljo Heating, Cooling & PlumbingHow Job match is calculatedBuilt only from reviews Google tagged “Cleaning”:Stars on this job 55%5.00★Number of such jobs 25%6Overall Experts Score 20%95Job match= 81Stars 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.81
Zark Heating & Cooling Inc.How Job match is calculatedBuilt only from reviews Google tagged “Cleaning”:Stars on this job 55%5.00★Number of such jobs 25%4Overall Experts Score 20%97Job match= 79Stars 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.79
Service 1 Plumbing, Heating & A/C, Inc.How Job match is calculatedBuilt only from reviews Google tagged “Cleaning”:Stars on this job 55%5.00★Number of such jobs 25%5Overall Experts Score 20%91Job match= 79Stars 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.79Job match = this company’s ★ on reviews Google tagged “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 cleaning
Service Express Heating and Air C…Kenny was excellent with the Dryer Cleaning we booked. He worked quickly, inspecting and cleaning the dryer itself and going up onto the roof in case there was lint backup at the end of the ventilation. Overall Kenny always does a great job and is very polite. Thank you Kenny!
Energy Services Air Conditioning …Lowry did a very good job checking and cleaning the furnace. He is knowledgeable and offered suggestions. Also took the time to clearly explain things. Keep up the good work!
Comfort Zone ServiceThis Company is Outstanding! Been with comfort Zone for several years now and I couldn’t be happier! Molly is always a great voice to hear when scheduling. You don’t have to wait days for a service call/call back, they are flexible with your schedule, and always on time with a curtsy heads up before they arrive.…
Deljo Heating, Cooling & PlumbingThank you, Deljo service crew (Angel and Ernesto), for performing an excellent job. We appreciate your honesty in not adding any add-ons.
Service Express Heating and Air C…Christian was great… took care of our problem and explained everything clearly…very pleased
Service Express Heating and Air C…Kenny was prompt, professional, and thorough! I’m glad my heating system is prepared for the winter! And my dryer vent is nice and clean!
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 at a glance
How the 10 boiler installers we rated 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.