503 HVAC contractors ranked by CR ScoreUpdated 0 paid placements in this rankingHow we rank →
Best overall in Castle Rock: Nytech Heating, Cooling, and Plumbing, CR Score 67/100; 5.0★ from 2,828 Google reviews; open 24/7.
Best for emergencies (open 24/7): Mountain Air Comfort Systems, posts 24/7 hours; ranked #2 of 503.
Most-reviewed: Plumbline Services, 9,085 Google reviews at 4.7★, the most of 503 ranked; ranked #3.
Rankings can't be bought. Contractors can't pay to change their rank or score. How we rank
503 Castle Rock HVAC contractors are ranked here by CR Score, from ten published factors. 197 are open 24/7, 355 open Saturdays and 272 open Sundays, based on posted hours. The median Google rating is 4.9★ across 503 rated businesses.
| Rank | Business | CR Score | Google rating | Based in | Hours | Best for |
|---|---|---|---|---|---|---|
| 1 | Nytech Heating, Cooling, and Plumbing | 67 | 5.0★ (2,828) | Castle Rock | 24/7 | Overall |
| 2 | Mountain Air Comfort Systems | 63 | 4.9★ (285) | Castle Rock | 24/7 | Emergencies |
| 3 | Plumbline Services | 63 | 4.7★ (9,085) | Centennial, 15 mi away | 24/7 | Most reviews |
| 4 | Aim High HVAC | 62 | 5.0★ (760) | Littleton, 13 mi away | 24/7 | — |
| 5 | 1st Choice Pro Services | 62 | 4.9★ (969) | Parker, 12 mi away | 24/7 | — |
| 6 | Elkhorn Heating, Air Conditioning, Plumbing & Electrical | 62 | 4.9★ (1,799) | Littleton, 16 mi away | 24/7 | — |
| 7 | 888 Heating & Air Conditioning | 62 | 4.9★ (1,310) | Centennial, 15 mi away | 24/7 | — |
| 8 | Allied Heating & Air Conditioning | 62 | 4.6★ (250) | Castle Rock | 24/7 | — |
| 9 | Colorado Bear Heating & Air | 61 | 5.0★ (165) | Castle Rock | Sat · Sun · Evenings | — |
| 10 | Behold Heating and Cooling | Denver HVAC | 61 | 5.0★ (371) | Englewood, 12 mi away | 24/7 | — |
Ordered by CR Score, a 0–100 score from ten published factors. Paid placement never changes the order.
Scores below: based on 8 of 10 factors; credentials and recency not yet collected. Hatched segments mark factors we don't have yet.
Ranked #1 because of its Google rating and trade focus: 5.0★ from 2,828 Google reviews, listed on Google as “HVAC contractor”.
Based in Castle Rock
Ranked #2 because of its Google rating and trade focus: 4.9★ from 285 Google reviews, listed on Google as “HVAC contractor”.
Based in Centennial, 15 mi away
Ranked #3 because of its Google rating and review volume: 4.7★ from 9,085 Google reviews, the most in Castle Rock.
Based in Littleton, 13 mi away
Ranked #4 because of its Google rating and trade focus: 5.0★ from 760 Google reviews, listed on Google as “HVAC contractor”.
Based in Parker, 12 mi away
Ranked #5 because of its Google rating and trade focus: 4.9★ from 969 Google reviews, listed on Google as “HVAC contractor”.
Based in Littleton, 16 mi away
Ranked #6 because of its Google rating and trade focus: 4.9★ from 1,799 Google reviews, listed on Google as “HVAC contractor”.
Based in Centennial, 15 mi away
Ranked #7 because of its Google rating and trade focus: 4.9★ from 1,310 Google reviews, listed on Google as “HVAC contractor”.
Based in Castle Rock
Ranked #8 because of its Google rating and trade focus: 4.6★ from 250 Google reviews, listed on Google as “HVAC contractor”.
Based in Castle Rock
Ranked #9 because of its Google rating and trade focus: 5.0★ from 165 Google reviews, listed on Google as “HVAC contractor”.
Based in Englewood, 12 mi away
Ranked #10 because of its Google rating and trade focus: 5.0★ from 371 Google reviews, listed on Google as “HVAC contractor”.
Based in Castle Rock
Ranked #11 because of its Google rating and trade focus: 4.8★ from 89 Google reviews, listed on Google as “HVAC contractor”.
Based in Parker, 12 mi away
Ranked #12 because of its Google rating and trade focus: 4.9★ from 490 Google reviews, listed on Google as “HVAC contractor”.
Based in Castle Rock
Ranked #13 because of its Google rating and review volume: 4.7★ from 1,722 Google reviews.
Based in Littleton, 12 mi away
Ranked #14 because of its Google rating and trade focus: 4.9★ from 405 Google reviews, listed on Google as “HVAC contractor”.
Based in Littleton, 15 mi away
Ranked #15 because of its Google rating and trade focus: 4.9★ from 732 Google reviews, listed on Google as “HVAC contractor”.
Based in Castle Rock
Ranked #16 because of its Google rating and trade focus: 4.9★ from 55 Google reviews, listed on Google as “HVAC contractor”.
Based in Centennial, 14 mi away
Ranked #17 because of its Google rating and trade focus: 4.7★ from 4,177 Google reviews, listed on Google as “HVAC contractor”.
Based in Parker, 11 mi away
Ranked #18 because of its Google rating and trade focus: 4.8★ from 512 Google reviews, listed on Google as “HVAC contractor”.
Based in Castle Rock
Ranked #19 because of its Google rating and trade focus: 4.8★ from 61 Google reviews, listed on Google as “HVAC contractor”.
Based in Castle Rock
Ranked #20 because of its Google rating and trade focus: 4.8★ from 61 Google reviews, listed on Google as “HVAC contractor”.
Based in Castle Rock
Ranked #21 because of its Google rating and trade focus: 4.9★ from 150 Google reviews, listed on Google as “HVAC contractor”.
Based in Parker, 13 mi away
Ranked #22 because of its Google rating and trade focus: 4.8★ from 642 Google reviews, listed on Google as “Heating contractor”.
Based in Castle Rock
Ranked #23 because of its Google rating and trade focus: 4.8★ from 52 Google reviews, listed on Google as “HVAC contractor”.
Based in Centennial, 15 mi away
Ranked #24 because of its Google rating and trade focus: 4.9★ from 466 Google reviews, listed on Google as “HVAC contractor”.
Based in Parker, 11 mi away
Ranked #25 because of its Google rating and trade focus: 5.0★ from 149 Google reviews, listed on Google as “HVAC contractor”.
#1 to #25 are shown in full above. Here are #26 to #50, in CR Score order; each links to its profile. We publish the top 50 of 503 ranked HVAC contractors here; the rest are on their profiles.
20 more HVAC contractors within 25 mi that we can't rank yet: too few reviews, or a trade we couldn't confirm. Listed A to Z.
National price ranges in USD, not adjusted for Castle Rock. Each row names its basis and the month we checked it.
| Job | Low | Typical | High | Basis | Checked |
|---|---|---|---|---|---|
| AC replacement | $3,887 | $5,978 | $8,073 | Per system, installed (unit plus labor); typical range of customer-reported jobs. US national range | October 2026 |
| Furnace replacement | $2,823 | $4,814 | $6,896 | Per system, installed; typical range of customer-reported jobs. US national range | October 2026 |
In Colorado, furnace and heat pump calls peak in the coldest winter weeks and AC calls in summer heat waves. Spring and fall are the easiest times to book maintenance or a replacement.
We scored 503 Castle Rock HVAC contractors on ten factors, weighted as shown. A business is ranked when its trade is confirmed and it has 3 or more Google reviews or a claimed profile. A business with no Google reviews scores zero on rating, review volume and recency. Other unknown factors are left out, not counted as zero. Scores last refreshed October 22, 2026.
Paid placement never changes a rank or score. Featured businesses are paid, labelled, limited to 3 and shown above the ranking, outside it.
| Factor | Weight | Computed from | In Castle Rock data |
|---|---|---|---|
| Reputation | 25% | Google star rating, adjusted for how many reviews back it | Measured |
| Credentials | 15% | Active state license, bond and workers’ comp on file | Not yet collected |
| Review volume | 10% | Number of Google reviews, compared with the most-reviewed business on the list | Measured |
| Recency | 5% | Share of reviews from the last 12 months | Not yet collected |
| Availability | 5% | Weekly open hours, Saturday, Sunday, 24/7 or same-day | Measured |
| Trade focus | 10% | How clearly the business does this trade (its Google category and name) | Measured |
| Proximity | 5% | Based in the city scores highest, less the farther away it is | Measured |
| Claimed profile | 10% | The business has claimed its ContractorsRanked profile (free or paid earn the same) | Measured |
| Partnered | 5% | The business links to ContractorsRanked from its own website with our badge, checked periodically | Measured |
| ContractorsRanked reviews | 10% | Verified customer reviews collected by ContractorsRanked: their rating and how many there are | Measured |