190 HVAC contractors ranked by CR ScoreUpdated 0 paid placements in this rankingHow we rank →
Best overall in St. Catharines: Reliance Heating, Air Conditioning & Plumbing, CR Score 67/100; 4.8★ from 2,986 Google reviews; open 24/7.
Best for emergencies (open 24/7): Mr. Furnace Heating and Air Conditioning, posts 24/7 hours; ranked #2 of 190.
Most-reviewed: T-Mark Plumbing, Heating & Cooling- Buffalo, 3,978 Google reviews at 4.9★, the most of 190 ranked; ranked #7.
Rankings can't be bought. Contractors can't pay to change their rank or score. How we rank
190 St. Catharines HVAC contractors are ranked here by CR Score, from ten published factors. 76 are open 24/7, 122 open Saturdays and 99 open Sundays, based on posted hours. The median Google rating is 4.8★ across 190 rated businesses.
| Rank | Business | CR Score | Google rating | Based in | Hours | Best for |
|---|---|---|---|---|---|---|
| 1 | Reliance Heating, Air Conditioning & Plumbing | 67 | 4.8★ (2,986) | St. Catharines | 24/7 | Overall |
| 2 | Mr. Furnace Heating and Air Conditioning | 67 | 4.8★ (2,672) | St. Catharines | 24/7 | Emergencies |
| 3 | Enercare | 66 | 4.6★ (2,788) | St. Catharines | 24/7 | — |
| 4 | MacKay Heating & Cooling | 64 | 4.8★ (349) | St. Catharines | 24/7 | — |
| 5 | MarZ Heating & Cooling Inc. | 63 | 5.0★ (114) | St. Catharines | 24/7 | — |
| 6 | Evans Heating & Cooling | 63 | 4.8★ (822) | Niagara Falls, 14 km away | 24/7 | — |
| 7 | T-Mark Plumbing, Heating & Cooling- Buffalo | 62 | 4.9★ (3,978) | Buffalo, 40 km away | 24/7 | Most reviews |
| 8 | Roy's Plumbing, Heating, Cooling & Electrical | 62 | 4.8★ (3,074) | Tonawanda, 34 km away | 24/7 | — |
| 9 | Tropical Heating & Cooling - Niagara Falls | 62 | 4.9★ (405) | Niagara Falls, 18 km away | 24/7 | — |
| 10 | Superior Plumbing & Heating of St. Catharines | 62 | 4.9★ (60) | St. Catharines | 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: 4.8★ from 2,986 Google reviews, listed on Google as “HVAC contractor”.
Based in St. Catharines
Ranked #2 because of its Google rating and trade focus: 4.8★ from 2,672 Google reviews, listed on Google as “HVAC contractor”.
Based in St. Catharines
Ranked #3 because of its Google rating and trade focus: 4.6★ from 2,788 Google reviews, listed on Google as “HVAC contractor”.
Based in St. Catharines
Ranked #4 because of its Google rating and trade focus: 4.8★ from 349 Google reviews, listed on Google as “HVAC contractor”.
Based in St. Catharines
Ranked #5 because of its Google rating and trade focus: 5.0★ from 114 Google reviews, listed on Google as “HVAC contractor”.
Based in Niagara Falls, 14 km away
Ranked #6 because of its Google rating and trade focus: 4.8★ from 822 Google reviews, listed on Google as “HVAC contractor”.
Based in Buffalo, 40 km away
Ranked #7 because of its Google rating and review volume: 4.9★ from 3,978 Google reviews, the most in St. Catharines.
Based in Tonawanda, 34 km away
Ranked #8 because of its Google rating and trade focus: 4.8★ from 3,074 Google reviews, listed on Google as “HVAC contractor”.
Based in Niagara Falls, 18 km away
Ranked #9 because of its Google rating and trade focus: 4.9★ from 405 Google reviews, listed on Google as “HVAC contractor”.
Based in St. Catharines
Ranked #10 because of its Google rating and trade focus: 4.9★ from 60 Google reviews, listed on Google as “HVAC contractor”.
Based in Grand Island, 25 km away
Ranked #11 because of its Google rating and trade focus: 5.0★ from 384 Google reviews, listed on Google as “HVAC contractor”.
Based in Niagara Falls, 20 km away
Ranked #12 because of its Google rating and trade focus: 4.9★ from 877 Google reviews, listed on Google as “Air conditioning contractor”.
Based in Niagara Falls, 14 km away
Ranked #13 because of its Google rating and trade focus: 5.0★ from 336 Google reviews, listed on Google as “HVAC contractor”.
Based in Welland, 20 km away
Ranked #14 because of its Google rating and trade focus: 4.9★ from 560 Google reviews, listed on Google as “HVAC contractor”.
Based in Amherst, 39 km away
Ranked #15 because of its Google rating and trade focus: 4.9★ from 1,236 Google reviews, listed on Google as “HVAC contractor”.
Based in St. Catharines
Ranked #16 because of its Google rating and trade focus: 4.9★ from 57 Google reviews, listed on Google as “HVAC contractor”.
Based in Thorold, 6 km away
Ranked #17 because of its Google rating and trade focus: 5.0★ from 551 Google reviews, listed on Google as “HVAC contractor”.
Based in St. Catharines
Ranked #18 because of its Google rating and trade focus: 4.6★ from 20 Google reviews, listed on Google as “HVAC contractor”.
Based in Niagara Falls, 20 km away
Ranked #19 because of its Google rating and trade focus: 4.8★ from 123 Google reviews, listed on Google as “HVAC contractor”.
Based in St. Catharines
Ranked #20 because of its Google rating and trade focus: 4.5★ from 90 Google reviews, listed on Google as “HVAC contractor”.
Based in Kenmore, 36 km away
Ranked #21 because of its Google rating and trade focus: 4.7★ from 796 Google reviews, listed on Google as “HVAC contractor”.
Based in St. Catharines
Ranked #22 because of its Google rating and trade focus: 5.0★ from 64 Google reviews, listed on Google as “HVAC contractor”.
Based in Welland, 11 km away
Ranked #23 because of its Google rating and trade focus: 5.0★ from 27 Google reviews, listed on Google as “HVAC contractor”.
Based in Niagara Falls, 13 km away
Ranked #24 because of its Google rating and trade focus: 4.6★ from 64 Google reviews, listed on Google as “HVAC contractor”.
Based in St. Catharines
Ranked #25 because of its Google rating and trade focus: 4.6★ from 11 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 190 ranked HVAC contractors here; the rest are on their profiles.
20 more HVAC contractors within 40 km that we can't rank yet: too few reviews, or a trade we couldn't confirm. Listed A to Z.
| Business | Google rating | Distance |
|---|---|---|
| ACE Plumbing & Heating Corp | In St. Catharines | |
| Air Masters Heating And Cooling | 5.0★ (9) | 21 km |
| Ambiance Comfort Mechanical Ltd | In St. Catharines | |
| Castle Plumbing & Heating Inc. | In St. Catharines | |
| Complete Comfort Niagara | In St. Catharines | |
| EAS Heating & Air Cond | 2.5★ (2) | In St. Catharines |
| Ed's Pipeworks | 4.6★ (33) | In St. Catharines |
| Enviro Niagara | 5.0★ (1) | In St. Catharines |
| Greg's Plumbing and Heating Inc. | 5.0★ (5) | 16 km |
| Guest Plumbing & HVAC | 5.0★ (1) | In St. Catharines |
| Hamilton Air Systems Inc | 4.9★ (35) | 36 km |
| Haye Technical Corporation | In St. Catharines | |
| Impact Mechanical Hvac | In St. Catharines | |
| Jamie Janzen Plumbing & Heating Inc | In St. Catharines | |
| Mario Palmer Heating and Cooling Inc | 5.0★ (3) | 15 km |
| Niagara Home Heating | 5.0★ (3) | 14 km |
| Plumr Plumbing & Heating | 4.9★ (121) | 20 km |
| Regional Mechanical (Niagara) Inc. | 5.0★ (1) | In St. Catharines |
| Reynolds Heating Plumbing & AC | In St. Catharines | |
| S L Heating Inc | 3.8★ (5) | 10 km |
US national ranges converted to CAD, not adjusted for St. Catharines. Each row names its basis and the month we checked it.
| Job | Low | Typical | High | Basis | Checked |
|---|---|---|---|---|---|
| AC replacement | CA$5,460 | CA$8,400 | CA$11,350 | Per system, installed (unit plus labor); typical range of customer-reported jobs. US national range converted at 1.4054 CAD per USD (Bank of Canada, October 20, 2026) | October 2026 |
| Furnace replacement | CA$3,970 | CA$6,770 | CA$9,690 | Per system, installed; typical range of customer-reported jobs. US national range converted at 1.4054 CAD per USD (Bank of Canada, October 20, 2026) | October 2026 |
In Ontario, 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 190 St. Catharines 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 St. Catharines 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 |