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.
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Best boiler installers for thermostat repair
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Service Express Heating and Air ConditioningHow Job match is calculatedBuilt only from reviews Google tagged “Thermostat repair”:Stars on this job 55%4.92★Number of such jobs 25%13Overall 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
Energy Services Air Conditioning & Heating Co. & ElectricalHow Job match is calculatedBuilt only from reviews Google tagged “Thermostat repair”:Stars on this job 55%5.00★Number of such jobs 25%8Overall 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
Zark Heating & Cooling Inc.How Job match is calculatedBuilt only from reviews Google tagged “Thermostat repair”:Stars on this job 55%5.00★Number of such jobs 25%5Overall Experts Score 20%97Job 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
Rousculp's Heating and CoolingHow Job match is calculatedBuilt only from reviews Google tagged “Thermostat repair”:Stars on this job 55%5.00★Number of such jobs 25%5Overall 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
Maertin Heating & CoolingHow Job match is calculatedBuilt only from reviews Google tagged “Thermostat repair”:Stars on this job 55%5.00★Number of such jobs 25%4Overall Experts Score 20%93Job match= 85Stars 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.85
Service 1 Plumbing, Heating & A/C, Inc.How Job match is calculatedBuilt only from reviews Google tagged “Thermostat repair”:Stars on this job 55%5.00★Number of such jobs 25%4Overall Experts Score 20%91Job 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.84Job match = this company’s ★ on reviews Google tagged “Thermostat 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 thermostat repair
Rousculp's Heating and CoolingGreat service. Great technician. Polite, knowledgeable, so courteous. Thank you!
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.
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.
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…
Maertin Heating & CoolingMaertin did an absolutely wonderful job replacing two old heat exchanger furnaces with state of the art high efficiency gas furnaces. It involved complex work that required working in tight spaces. Appearance is much better than before and couldn’t be happier with the results!
Service 1 Plumbing, Heating & A/C…My AC went out and I called to see if they could come and diagnose the problem. They came after hours on the same day I called and immediately fixed the problem. The rep installed a new thermostat. The rep was very knowledgeable and polite and I was very happy it was able to be fixed so promptly since it was very…
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.