The Best HVAC Contractors in Sunnyvale, CA
We graded 9 companies on seven things customers actually report: satisfaction, reliability, workmanship, value, momentum, track record and how owners handle complaints.
From 117,533 Google reviews of 113 top-rated HVAC contractors nationwide; 9 of them in Sunnyvale, CA. Updated November 1, 2026.
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Best HVAC contractors in Sunnyvale for thermostat repair
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Same Day Air Conditioning & HeatingHow Job match is calculatedBuilt only from reviews Google tagged “Thermostat repair”:Stars on this job 55%4.88★Number of such jobs 25%8Overall Experts Score 20%63Job match= 84Stars are pulled toward the category average (4.90★) 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
All HVAC & General ConstructionHow Job match is calculatedBuilt only from reviews Google tagged “Thermostat repair”:Stars on this job 55%5.00★Number of such jobs 25%3Overall Experts Score 20%71Job match= 79Stars are pulled toward the category average (4.90★) 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 “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
Same Day Air Conditioning & Heati…The technicians were very professional and worked their tail off. I highly recommend them to anyone and everyone.
All HVAC & General ConstructionVictor was very professional and knowledgeable. He was on time and thoroughly explains what he was doing. He also gave pointers on how to keep my AC & Heating clean and filters advice.
Same Day Air Conditioning & Heati…Gabriel and Same Day Airconditioning are a company I highly recommend. They serviced my issue literally on the same day. Gabriel is a highly skilled, professional and competent technician and has successfully provided service to us in the past too. Mine is a very old airconditioner. However, I was fully assured…
All HVAC & General ConstructionMy heater is not working and I called the service for fixing. Victor came and quickly identify the issue is the thermostat and show me different options to fix this problem. He is very professional and honest. I would like to recommend him to anyone has the same issue
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 HVAC contractors).
| # | 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). |
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| 1 |  Promax Service GroupSunnyvale, CA | A 100How 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%100+58.7Reliability 26%99+25.8Value 15%100+15.2Experts Score= 100Not 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– | 5.00 | $1.2k |
| 2 |  Nur HVACSunnyvale, CA | 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%96+52.4Reliability 24%98+23.8Value 14%100+14.1Replies to reviews 7%81+5.7Experts Score= 96Grade A: A = 80+, B = 60–79, C = 40–59, D = 20–39. Needs 10+ reviews. | AAAAAA | 4.95 | $1.1k |
| 3 |  United HVAC, Plumbing & ElectricalSunnyvale, CA | 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 59%98+57.5Reliability 26%97+25.3Value 15%90+13.7Craft & service penalty99−0.1Experts Score= 96Not 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. | AAAAA– | 4.98 | $549 |
| 4 |  Your Appliance, Refrigeration & HVAC repairSunnyvale, CA | 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%96+52.4Reliability 24%99+24Value 14%95+13.4Replies to reviews 7%85+6Experts Score= 96Grade A: A = 80+, B = 60–79, C = 40–59, D = 20–39. Needs 10+ reviews. | AA–AAA | 4.96 | $287 |
| 5 |  United HVAC, Plumbing & ElectricalSunnyvale, CA | 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%94+51.3Reliability 24%95+23Value 14%100+14.1Replies to reviews 7%100+7.1Craft & service penalty98−0.2Experts Score= 95Grade A: A = 80+, B = 60–79, C = 40–59, D = 20–39. Needs 10+ reviews. | AAAAAA | 4.94 | $824 |
| 6 |  Made Simple Heating And AirSunnyvale, CA | 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%94+51.3Reliability 24%93+22.5Value 14%100+14.1Replies to reviews 7%100+7.1Craft & service penalty99−0.1Experts Score= 95Grade A: A = 80+, B = 60–79, C = 40–59, D = 20–39. Needs 10+ reviews. | AAAAAA | 4.95 | $1.2k |
| 7 |  United HVAC, Plumbing & ElectricalSunnyvale, CA | A 88How 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%89+21.6Value 14%81+11.5Replies to reviews 7%84+5.9Experts Score= 88Grade A: A = 80+, B = 60–79, C = 40–59, D = 20–39. Needs 10+ reviews. | AA–AAA | 4.90 | $460 |
| 8 | All HVAC & General ConstructionSunnyvale, CA | B 71How 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%78+42.5Reliability 24%59+14.3Value 14%100+14.1Replies to reviews 7%92+6.5Craft & service penalty35−6.5Experts Score= 71Grade B: A = 80+, B = 60–79, C = 40–59, D = 20–39. Needs 10+ reviews. | BCDAAA | 4.75 | — |
| 9 | Same Day Air Conditioning & HeatingSunnyvale, CA | B 63How 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%72+39.3Reliability 24%65+15.8Value 14%87+12.3Replies to reviews 7%22+1.6Craft & service penalty46−5.4Experts Score= 63Grade B: A = 80+, B = 60–79, C = 40–59, D = 20–39. Needs 10+ reviews. | BBCAAD | 4.71 | $135 |
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 | $135 | $295 | 98% |
| A/C system maintenance | $39 | $192 | $393 | 98% |
| HVAC system repair | $205 | $406 | $959 | 96% |
| A/C system repair | $216 | $383 | $807 | 97% |
| Install AC | $1.6k | $2.1k | $3.2k | 98% |
| Heating system maintenance | $39 | $124 | $251 | 98% |
| Heating system installation | $1.4k | $1.9k | $2.8k | 98% |
| Repair HVAC | $224 | $359 | $535 | 96% |
| Heating system repair | $161 | $453 | $1.2k | 97% |
| Installation | $1.1k | $2.1k | $2.8k | 99% |
| Install thermostat | $50 | $148 | $437 | 98% |
| HVAC duct & vent installation | $1.2k | $1.9k | $2.8k | 95% |
HVAC Contractors in Sunnyvale, CA at a glance
How the 9 HVAC contractors we rated in Sunnyvale, CA compare, and what customers praise most.
Experts Score grades
A = score 80+, F = below 20.
- Grade A778%
- Grade B222%
- Grade C00%
- Grade D00%
- Grade F00%
Google ratings
Average stars per company.
- 4.90★ and up778%
- 4.80–4.89★00%
- 4.60–4.79★222%
- Below 4.60★00%
What customers praise
Share of Google review highlights.
- Quality22,37820%
- Professionalism27,63324%
- Responsiveness23,45921%
- Punctuality23,09820%
- Value16,77115%
Was the price fair?
All price verdicts left with reviews.
- Great price6,30133%
- Reasonable10,64856%
- Overpriced5893%
- Not sure1,4898%
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.