1,129 HVAC contractors ranked by CR ScoreUpdated 0 paid placements in this rankingHow we rank →
Best overall in Chelmsford: MillTown Plumbing, Heating, Cooling and Electrical, CR Score 66/100; 4.8★ from 2,927 Google reviews; open 24/7.
Best for emergencies (open 24/7): Papalia Home Services, posts 24/7 hours; ranked #2 of 1,129.
Most-reviewed: Heritage Home Service, 7,956 Google reviews at 4.8★, the most of 1,129 ranked; ranked #20.
Rankings can't be bought. Contractors can't pay to change their rank or score. How we rank
1,129 Chelmsford HVAC contractors are ranked here by CR Score, from ten published factors. 341 are open 24/7, 614 open Saturdays and 463 open Sundays, based on posted hours. The median Google rating is 4.9★ across 1,129 rated businesses.
| Rank | Business | CR Score | Google rating | Based in | Hours | Best for |
|---|---|---|---|---|---|---|
| 1 | MillTown Plumbing, Heating, Cooling and Electrical | 66 | 4.8★ (2,927) | Chelmsford | 24/7 | Overall |
| 2 | Papalia Home Services | 65 | 4.9★ (3,978) | Acton, 10 mi away | 24/7 | Emergencies |
| 3 | 128 Plumbing, Heating, Cooling & Electric | 65 | 5.0★ (443) | Chelmsford | 24/7 | — |
| 4 | A. Fagundes Plumbing & Heating Inc. | 64 | 4.8★ (1,626) | Billerica, 5 mi away | 24/7 | — |
| 5 | Central Cooling & Heating | 64 | 4.9★ (3,169) | Woburn, 13 mi away | 24/7 | — |
| 6 | Mike Giasullo Oil Burner Service Inc. | 64 | 5.0★ (476) | Billerica, 4 mi away | 24/7 | — |
| 7 | Heritage Home Service | 64 | 4.8★ (3,352) | Wilmington, 11 mi away | 24/7 | — |
| 8 | 128 Plumbing, Heating, Cooling & Electric | 63 | 4.9★ (3,912) | Wakefield, 17 mi away | 24/7 | — |
| 9 | Denommee Plumbing, HVAC & Electric | 63 | 4.7★ (427) | Chelmsford | 24/7 | — |
| 10 | Nashoba Air & BoilerWorks | 63 | 4.9★ (1,833) | Acton, 7 mi away | Sat · Sun · Evenings | — |
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: 4.8★ from 2,927 Google reviews, listed on Google as “HVAC contractor”.
Based in Acton, 10 mi away
Ranked #2 because of its Google rating and trade focus: 4.9★ from 3,978 Google reviews, listed on Google as “HVAC contractor”.
Based in Chelmsford
Ranked #3 because of its Google rating and trade focus: 5.0★ from 443 Google reviews, listed on Google as “HVAC contractor”.
Based in Billerica, 5 mi away
Ranked #4 because of its Google rating and trade focus: 4.8★ from 1,626 Google reviews, listed on Google as “Air conditioning contractor”.
Based in Woburn, 13 mi away
Ranked #5 because of its Google rating and trade focus: 4.9★ from 3,169 Google reviews, listed on Google as “HVAC contractor”.
Based in Billerica, 4 mi away
Ranked #6 because of its Google rating and trade focus: 5.0★ from 476 Google reviews, listed on Google as “Heating contractor”.
Based in Wilmington, 11 mi away
Ranked #7 because of its Google rating and trade focus: 4.8★ from 3,352 Google reviews, listed on Google as “HVAC contractor”.
Based in Wakefield, 17 mi away
Ranked #8 because of its Google rating and trade focus: 4.9★ from 3,912 Google reviews, listed on Google as “HVAC contractor”.
Based in Chelmsford
Ranked #9 because of its Google rating and trade focus: 4.7★ from 427 Google reviews, listed on Google as “HVAC contractor”.
Based in Acton, 7 mi away
Ranked #10 because of its Google rating and trade focus: 4.9★ from 1,833 Google reviews, listed on Google as “HVAC contractor”.
Based in Chelmsford
Ranked #11 because of its Google rating and trade focus: 4.9★ from 183 Google reviews, listed on Google as “HVAC contractor”.
Based in Fitchburg, 11 mi away
Ranked #12 because of its Google rating and trade focus: 4.9★ from 1,275 Google reviews, listed on Google as “HVAC contractor”.
Based in Nashua, 12 mi away
Ranked #13 because of its Google rating and trade focus: 4.9★ from 793 Google reviews, listed on Google as “HVAC contractor”.
Based in Stoneham, 16 mi away
Ranked #14 because of its Google rating and trade focus: 4.9★ from 4,377 Google reviews, listed on Google as “HVAC contractor”.
Based in Lowell, 2 mi away
Ranked #15 because of its Google rating and trade focus: 4.8★ from 185 Google reviews, listed on Google as “Air conditioning contractor”.
Based in Pinehurst, 5 mi away
Ranked #16 because of its Google rating and trade focus: 4.8★ from 265 Google reviews, listed on Google as “HVAC contractor”.
Based in Wilmington, 12 mi away
Ranked #17 because of its Google rating and trade focus: 4.6★ from 2,076 Google reviews, listed on Google as “HVAC contractor”.
Based in North Andover, 14 mi away
Ranked #18 because of its Google rating and trade focus: 5.0★ from 562 Google reviews, listed on Google as “HVAC contractor”.
Based in Tewksbury, 9 mi away
Ranked #19 because of its Google rating and trade focus: 4.8★ from 444 Google reviews, listed on Google as “Air conditioning contractor”.
Based in Auburn, 25 mi away
Ranked #20 because of its Google rating and review volume: 4.8★ from 7,956 Google reviews, the most in Chelmsford.
Based in Watertown, 19 mi away
Ranked #21 because of its Google rating and trade focus: 4.8★ from 2,862 Google reviews, listed on Google as “HVAC contractor”.
Based in Lowell, 2 mi away
Ranked #22 because of its Google rating and trade focus: 4.9★ from 94 Google reviews, listed on Google as “HVAC contractor”.
Based in Danvers, 23 mi away
Ranked #23 because of its Google rating and trade focus: 4.8★ from 4,220 Google reviews, listed on Google as “HVAC contractor”.
Based in Watertown, 18 mi away
Ranked #24 because of its Google rating and trade focus: 4.8★ from 1,625 Google reviews, listed on Google as “HVAC contractor”.
Based in Chelmsford
Ranked #25 because of its Google rating and review volume: 4.9★ from 619 Google reviews.
#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 1,129 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.
| Business | Google rating | Distance |
|---|---|---|
| Air Temperature Control | 5.0★ (1) | In Chelmsford |
| Andy's Heating and Cooling llc | In Chelmsford | |
| B J Doyle Heating & Air Conditioning | 5.0★ (2) | 7 mi |
| Burlington Plumbing & Heating | 3.0★ (2) | 5 mi |
| Carlson Hvac Inc | 3.0★ (2) | 6 mi |
| Constant Temperature Systems | 3.0★ (2) | 8 mi |
| Dracut Plumbing & Heating | 3.0★ (2) | 8 mi |
| Ferris Plumbing, Heating & Air | 4.9★ (77) | 10 mi |
| Hassan Plumbing & Heating | In Chelmsford | |
| Hunter & Sons AC Heating & Cooling | 4.8★ (71) | 3 mi |
| James Gardner Plumbing & Heating LLC | 5.0★ (2) | 9 mi |
| Kilpatrick HVAC | 5.0★ (2) | 4 mi |
| Mahoney Plumbing & Heating | 5.0★ (2) | 3 mi |
| Nashoba Air and Boilerworks | In Chelmsford | |
| Reliable Refrigeration Inc | 5.0★ (2) | 4 mi |
| Shawsheen Air Services | In Chelmsford | |
| Sila Heating, Air Conditioning, Plumbing & Electrical | 4.7★ (483) | 16 mi |
| Super Service Today | 4.7★ (1,672) | 22 mi |
| ThermaCare Heating, Air & Electric | 4.9★ (84) | 10 mi |
| Tyngsboro Plumbing & Heating | 5.0★ (2) | 4 mi |
National price ranges in USD, not adjusted for Chelmsford. 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 Massachusetts, 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 1,129 Chelmsford 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 Chelmsford 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 |