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Best HVAC Contractors in Cornwall, ON (2026)

24 HVAC contractors ranked by CR ScoreUpdated 0 paid placements in this rankingHow we rank →

The short answer

  1. 1

    Best overall in Cornwall: Walker ClimateCare, CR Score 68/100; 4.8★ from 1,508 Google reviews; open 24/7.

  2. 2

    Best for emergencies (open 24/7): Superior Plumbing & Heating of Cornwall, posts 24/7 hours; ranked #2 of 24.

  3. 3

    Most-reviewed: Baker Heating & Air Conditioning Ltd., 326 Google reviews at 4.9★, the most of 24 ranked after Walker ClimateCare; ranked #3.

Rankings can't be bought. Contractors can't pay to change their rank or score. How we rank

24 Cornwall HVAC contractors are ranked here by CR Score, from ten published factors. 6 are open 24/7, 8 open Saturdays and 4 open Sundays, based on posted hours. The median Google rating is 4.8★ across 24 rated businesses.

Top 10 HVAC contractors in Cornwall at a glance

Top 10 HVAC contractors in Cornwall at a glance
RankBusinessCR ScoreGoogle ratingBased inHoursBest for
1Walker ClimateCare684.8★ (1,508)Cornwall24/7Overall
2Superior Plumbing & Heating of Cornwall614.3★ (74)Cornwall24/7Emergencies
3Baker Heating & Air Conditioning Ltd.604.9★ (326)Cornwall—Most reviews
4Wylie Mechanical595.0★ (53)CornwallSat · Evenings—
5SD&G Heating and Cooling595.0★ (7)Cornwall24/7—
6Casey Mechanical Inc584.9★ (111)Cornwall——
7M S Mechanical & Sons584.7★ (14)Cornwall24/7—
8McKay Mechanical Inc.574.8★ (51)Cornwall——
9Noble564.7★ (38)Cornwall——
10Behemoth Heating and Cooling HVAC Systems553.3★ (4)Cornwall24/7—

The 24 best HVAC contractors in Cornwall, ranked

Ordered by CR Score, a 0–100 score from ten published factors. Paid placement never changes the order.

  1. Ranked #1 in Cornwall

    #1 Walker ClimateCare

    Based in Cornwall

    68/100CR Score

    Ranked #1 because of its Google rating and review volume: 4.8★ from 1,508 Google reviews, the most in Cornwall.

    Based on 8 of 10 factors; credentials and recency not yet collected.

    • 4.8★ from 1,508 Google reviews
    • Open 24/7
    Hours
    Open 24 hours, 7 days
    Address
    1714 Vincent Massey Dr, Cornwall, ON K6H 5R6
    View profile for Walker ClimateCare(613) 416-7233

  4. #4 Wylie Mechanical

    Based in Cornwall

    59/100CR Score

    Ranked #4 because of its Google rating and trade focus: 5.0★ from 53 Google reviews, listed on Google as “HVAC contractor”.

    Based on 8 of 10 factors; credentials and recency not yet collected.

    • 5.0★ from 53 Google reviews
    Hours
    Mon–Sat 7 AM–7 PM · Sun closed
    View profile for Wylie Mechanical(613) 577-2726

  5. #5 SD&G Heating and Cooling

    Based in Cornwall

    59/100CR Score

    Ranked #5 because of its Google rating and trade focus: 5.0★ from 7 Google reviews, listed on Google as “HVAC contractor”.

    Based on 8 of 10 factors; credentials and recency not yet collected.

    • 5.0★ from 7 Google reviews
    • Open 24/7
    Hours
    Open 24 hours, 7 days
    Address
    17947 Headline Rd, Long Sault, ON K0C 1S0
    View profile for SD&G Heating and Cooling(613) 363-6153

  6. #6 Casey Mechanical Inc

    Based in Cornwall

    58/100CR Score

    Ranked #6 because of its Google rating and trade focus: 4.9★ from 111 Google reviews, listed on Google as “Air conditioning contractor”.

    Based on 8 of 10 factors; credentials and recency not yet collected.

    • 4.9★ from 111 Google reviews
    Hours
    Mon–Thu 8 AM–4 PM · Fri 8 AM–1 PM · Sat–Sun closed
    Address
    920 Carleton St, Cornwall, ON K6H 6B9
    View profile for Casey Mechanical Inc(613) 938-1210

  7. #7 M S Mechanical & Sons

    Based in Cornwall

    58/100CR Score

    Ranked #7 because of its Google rating and trade focus: 4.7★ from 14 Google reviews, listed on Google as “HVAC contractor”.

    Based on 8 of 10 factors; credentials and recency not yet collected.

    • 4.7★ from 14 Google reviews
    • Open 24/7
    Hours
    Open 24 hours, 7 days
    Address
    800 Campbell St, Cornwall, ON K6H 6L7
    View profile for M S Mechanical & Sons(613) 931-1887

  8. #8 McKay Mechanical Inc.

    Based in Cornwall

    57/100CR Score

    Ranked #8 because of its Google rating and trade focus: 4.8★ from 51 Google reviews, listed on Google as “HVAC contractor”.

    Based on 8 of 10 factors; credentials and recency not yet collected.

    • 4.8★ from 51 Google reviews
    Hours
    Mon–Fri 7:30 AM–4 PM · Sat–Sun closed
    Address
    880 Tenth St E, Cornwall, ON K6H 5T1
    View profile for McKay Mechanical Inc.(613) 932-1757

  9. #9 Noble

    Based in Cornwall

    56/100CR Score

    Ranked #9 because of its Google rating and trade focus: 4.7★ from 38 Google reviews, listed on Google as “HVAC contractor”.

    Based on 8 of 10 factors; credentials and recency not yet collected.

    • 4.7★ from 38 Google reviews
    Hours
    Mon–Fri 7 AM–5 PM · Sat–Sun closed
    Address
    2905 Copeland St, Cornwall, ON K6H 6L8
    View profile for Noble(613) 933-5600

  11. #11 AMS Plumbing and HVAC

    Based in Massena, 16 km away

    55/100CR Score

    Ranked #11 because of its Google rating and trade focus: 4.8★ from 39 Google reviews, listed on Google as “Plumber”.

    Based on 8 of 10 factors; credentials and recency not yet collected.

    • 4.8★ from 39 Google reviews
    • Open 24/7
    Hours
    Open 24 hours, 7 days
    View profile for AMS Plumbing and HVAC(315) 705-9422

  12. #12 Energy Wise Builders, LLC

    Based in Massena, 19 km away

    55/100CR Score

    Ranked #12 because of its Google rating and trade focus: 5.0★ from 26 Google reviews, listed on Google as “HVAC contractor”.

    Based on 8 of 10 factors; credentials and recency not yet collected.

    • 5.0★ from 26 Google reviews
    Hours
    Mon–Sat 8 AM–6 PM · Sun closed
    Address
    579 Brouse Rd, Massena, NY 13662
    View profile for Energy Wise Builders, LLC(315) 842-0645

  13. #13 Mike Paquette Mechanical

    Based in Cornwall

    55/100CR Score

    Ranked #13 because of its Google rating and trade focus: 5.0★ from 4 Google reviews, listed on Google as “HVAC contractor”.

    Based on 7 of 10 factors; credentials, recency and availability not yet collected.

    • 5.0★ from 4 Google reviews
    Address
    6550 Sapphire Dr, Cornwall, ON K6H 7J1
    View profile for Mike Paquette Mechanical(613) 931-0961

  14. #14 Boileau Mechanical Ltd

    Based in Cornwall

    55/100CR Score

    Ranked #14 because of its Google rating and trade focus: 5.0★ from 14 Google reviews, listed on Google as “HVAC contractor”.

    Based on 8 of 10 factors; credentials and recency not yet collected.

    • 5.0★ from 14 Google reviews
    Hours
    Mon–Fri 8 AM–4 PM · Sat–Sun closed
    Address
    6598 Vivian Cir, Cornwall, ON K6H 7J1
    View profile for Boileau Mechanical Ltd(613) 935-7114

  15. #15 Marc Viau Mechanical

    Based in Cornwall

    55/100CR Score

    Ranked #15 because of its Google rating and trade focus: 4.4★ from 25 Google reviews, listed on Google as “HVAC contractor”.

    Based on 8 of 10 factors; credentials and recency not yet collected.

    • 4.4★ from 25 Google reviews
    Hours
    Mon–Fri 8 AM–4 PM · Sat–Sun closed
    Address
    209 Eleventh St W, Cornwall, ON K6J 3B4
    View profile for Marc Viau Mechanical(613) 932-8180

  17. #17 Bellatin HVAC

    Based in Cornwall

    53/100CR Score

    Ranked #17 because of its Google rating and trade focus: 5.0★ from 6 Google reviews, listed on Google as “HVAC contractor”.

    Based on 8 of 10 factors; credentials and recency not yet collected.

    • 5.0★ from 6 Google reviews
    Hours
    Mon–Fri 7 AM–5 PM · Sat–Sun closed
    View profile for Bellatin HVAC(613) 362-3880

  18. #18 Pat Caron Heating and Air Conditioning | Heating Cornwall

    Based in Cornwall

    53/100CR Score

    Ranked #18 because of its Google rating and trade focus: 4.0★ from 15 Google reviews, listed on Google as “Air conditioning contractor”.

    Based on 8 of 10 factors; credentials and recency not yet collected.

    • 4.0★ from 15 Google reviews
    Hours
    Mon–Thu 8 AM–5 PM · Fri 8 AM–4 PM · Sat–Sun closed
    Address
    3050 Pitt St, Cornwall, ON K6K 1B1
    View profile for Pat Caron Heating and Air Conditioning | Heating Cornwall(613) 933-8144

  19. #19 Houde Mechanical Inc

    Based in Cornwall

    53/100CR Score

    Ranked #19 because of its Google rating and trade focus: 4.0★ from 22 Google reviews, listed on Google as “HVAC contractor”.

    Based on 8 of 10 factors; credentials and recency not yet collected.

    • 4.0★ from 22 Google reviews
    Hours
    Mon–Tue 9 AM–4 PM · Wed 9:30 AM–4 PM · Thu 9 AM–4 PM · Fri 9 AM–3 PM · Sat–Sun closed
    Address
    2905 Marleau Ave, Cornwall, ON K6H 6G5
    View profile for Houde Mechanical Inc(613) 931-1103

  21. #21 Marleau HVAC Services Ltd

    Based in Cornwall

    52/100CR Score

    Ranked #21 because of its Google rating and trade focus: 4.2★ from 5 Google reviews, listed on Google as “Air conditioning contractor”.

    Based on 8 of 10 factors; credentials and recency not yet collected.

    • 4.2★ from 5 Google reviews
    Hours
    Mon–Fri 8 AM–4 PM · Sat–Sun closed
    Address
    18077 Tyotown Rd, South Glengarry, ON K6H 7S7
    View profile for Marleau HVAC Services Ltd(613) 932-7548

  22. #22 Oscar Ladouceur & Son Ltd

    Based in Cornwall

    52/100CR Score

    Ranked #22 because of its Google rating and trade focus: 5.0★ from 3 Google reviews, listed on Google as “HVAC contractor”.

    Based on 8 of 10 factors; credentials and recency not yet collected.

    • 5.0★ from 3 Google reviews
    Hours
    Mon–Thu 7 AM–4:30 PM · Fri 7 AM–12 PM · Sat–Sun closed
    Address
    235 Saunders Dr, Cornwall, ON K6H 5R6
    View profile for Oscar Ladouceur & Son Ltd(613) 932-9492

  23. #23 Doug Gordon Refrigeration

    Based in Cornwall

    52/100CR Score

    Ranked #23 because of its Google rating and trade focus: 5.0★ from 3 Google reviews, listed on Google as “HVAC contractor”.

    Based on 8 of 10 factors; credentials and recency not yet collected.

    • 5.0★ from 3 Google reviews
    Hours
    Mon–Fri 8 AM–4:30 PM · Sat–Sun closed
    Address
    880 Tenth St E, Cornwall, ON K6H 5T1
    View profile for Doug Gordon Refrigeration(613) 935-4164

Also serving Cornwall

14 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.

Unranked HVAC contractors serving Cornwall
BusinessGoogle ratingDistance
ACE Plumbing & Heating4.0★ (1)In Cornwall
Bradford Plumbing & Heating39 km
Brent Walker Repair Svc5.0★ (1)In Cornwall
Clean All Environmental Services Inc.4.4★ (30)In Cornwall
Holmes Mech. LLC; Holmes Mechanical40 km
Houde Air - Hvac-Design & Consulting5.0★ (1)In Cornwall
Ionic Electrical Contracting Inc.4.8★ (97)In Cornwall
Laframboise Mechanical-Electrical Ltd4.2★ (5)In Cornwall
Lapierre Plumbing & HeatingIn Cornwall
quality-heating5.0★ (1)In Cornwall
Rj Rowell Plumbing & Heating11 km
Superior Plumbing & Heating3.0★ (1)16 km
The Water Heater Guy5.0★ (120)In Cornwall
Upstate Heating & Plumbing40 km

How much do HVAC contractors cost in Cornwall?

US national ranges converted to CAD, not adjusted for Cornwall. Each row names its basis and the month we checked it.

How much do HVAC contractors cost in Cornwall?
JobLowTypicalHighBasisChecked
AC replacementCA$5,460CA$8,400CA$11,350Per 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 replacementCA$3,970CA$6,770CA$9,690Per 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

When to hire an HVAC contractor in Ontario

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.

How we ranked Cornwall HVAC contractors

We scored 24 Cornwall 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.

Read the full method: formula, sources and exclusions

CR Score factors and weights
FactorWeightComputed fromIn Cornwall data
Reputation25%Google star rating, adjusted for how many reviews back itMeasured
Credentials15%Active state license, bond and workers’ comp on fileNot yet collected
Review volume10%Number of Google reviews, compared with the most-reviewed business on the listMeasured
Recency5%Share of reviews from the last 12 monthsNot yet collected
Availability5%Weekly open hours, Saturday, Sunday, 24/7 or same-dayMeasured
Trade focus10%How clearly the business does this trade (its Google category and name)Measured
Proximity5%Based in the city scores highest, less the farther away it isMeasured
Claimed profile10%The business has claimed its ContractorsRanked profile (free or paid earn the same)Measured
Partnered5%The business links to ContractorsRanked from its own website with our badge, checked periodicallyMeasured
ContractorsRanked reviews10%Verified customer reviews collected by ContractorsRanked: their rating and how many there areMeasured

HVAC contractors in Cornwall: frequently asked questions

Who is the best HVAC contractor in Cornwall?

By CR Score, the highest-ranked HVAC contractor in Cornwall, ON is Walker ClimateCare with a CR Score of 68/100. It has 4.8★ from 1,508 Google reviews. It is open 24/7. Superior Plumbing & Heating of Cornwall (#2) and Baker Heating & Air Conditioning Ltd. (#3) follow. We ranked 24 HVAC contractors on ten factors, last updated October 22, 2026.

How many HVAC contractors are there in Cornwall?

ContractorsRanked ranks 24 HVAC contractors serving Cornwall, ON. 20 of them are based in Cornwall; the rest serve it from nearby towns. Another 14 within 40 km are listed but not ranked yet. Counts are as of October 2026.

Which HVAC contractors in Cornwall are open 24/7?

6 ranked HVAC contractors in Cornwall post 24/7 hours. The highest-ranked are Walker ClimateCare (#1), Superior Plumbing & Heating of Cornwall (#2) and SD&G Heating and Cooling (#5). Hours come from each business's Google listing as of October 2026, so call to confirm.

Which HVAC contractors in Cornwall work on weekends?

8 of 24 ranked HVAC contractors post Saturday hours and 4 post Sunday hours. The highest-ranked open Saturdays are Walker ClimateCare (#1), Superior Plumbing & Heating of Cornwall (#2) and Wylie Mechanical (#4). Posted hours are office hours; crews may book weekend jobs separately.

How much does ac replacement cost in Cornwall?

AC replacement typically costs CA$5,460 to CA$11,350, with CA$8,400 typical (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)). This is a national range, not adjusted for Cornwall. Prices were last checked October 2026. Get at least two written quotes before you hire.

What Google rating do Cornwall HVAC contractors have?

The median Google rating among 24 rated HVAC contractors in Cornwall is 4.8★, with a median of 15 reviews. Walker ClimateCare has the most, 1,508 reviews, and ranks #1. We adjust ratings for review count, so a few five-star reviews cannot top the list.

When is the best time to hire an HVAC contractor in Cornwall?

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.

How does ContractorsRanked rank HVAC contractors?

Each HVAC contractor gets a 0–100 CR Score from ten published factors, led by reputation (25%), credentials (15%), review volume (10%) and trade focus (10%). A business with no Google reviews scores zero on rating, review volume and recency; other factors we cannot measure are left out. Only businesses with a confirmed trade and 3 or more reviews, or a claimed profile, are ranked.

Update log for Cornwall

  1. October 2026: CR Scores recalculated for 24 hvac contractors serving Cornwall.

More HVAC contractors and Cornwall pages