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Emergency HVAC Contractors in Cornwall, ON (2026)

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

6 of the 27 HVAC contractors on this list post 24/7 hours. 24/7 businesses come first, then same-day, each ranked by CR Score with availability weighted higher.

If you smell gas, leave the building now and call your gas utility or 911 from outside.

The short answer

  1. 1

    #1 for emergency heating and cooling in Cornwall: Walker ClimateCare, open 24/7.

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

Top emergency HVAC contractors in Cornwall at a glance

Top emergency HVAC contractors in Cornwall at a glance
RankBusinessCR ScoreGoogle ratingBased inHours
1Walker ClimateCare964.8★ (1,508)Cornwall24/7
2Superior Plumbing & Heating of Cornwall894.3★ (74)Cornwall24/7
3SD&G Heating and Cooling875.0★ (7)Cornwall24/7
4M S Mechanical & Sons864.7★ (14)Cornwall24/7
5Behemoth Heating and Cooling HVAC Systems833.3★ (4)Cornwall24/7
6AMS Plumbing and HVAC814.8★ (39)Massena, 16 km away24/7
7Mike Paquette Mechanical775.0★ (4)Cornwall—
8Cornelisse & Sons Heating & Cooling765.0★ (3)Cornwall—
9Express Plumbing & Heat Services734.5★ (11)Massena, 21 km away—
10J Riley Plumbing & Heating712.0★ (7)Massena, 16 km away—

Call an emergency HVAC contractor in Cornwall now

24/7 hours mean the business says its phone is answered around the clock. Arrival time depends on where the crew is. Ask for an arrival window when you call.

The 27 emergency HVAC contractors in Cornwall, ranked

24/7 first, then same-day service, then the rest. Each group is in CR Score order on emergency weights.

  1. Ranked #1 in Cornwall

    #1 Walker ClimateCare

    Based in Cornwall

    96/100CR Score

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

    Based on 6 of 8 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 M S Mechanical & Sons

    Based in Cornwall

    86/100CR Score

    Ranked #4 because of its Google rating and availability: 4.7★ from 14 Google reviews, open 24/7.

    Based on 6 of 8 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

  7. #7 Mike Paquette Mechanical

    Based in Cornwall

    77/100CR Score

    Ranked #7 because of its Google rating and trade focus: 5.0★ from 4 Google reviews, listed on Google as “HVAC contractor”.

    Based on 5 of 8 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

  12. #12 Casey Mechanical Inc

    Based in Cornwall

    65/100CR Score

    Ranked #12 because of its Google rating and trade focus: 4.9★ from 111 Google reviews, listed on Google as “Air conditioning contractor”.

    Based on 6 of 8 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

  13. #13 Wylie Mechanical

    Based in Cornwall

    64/100CR Score

    Ranked #13 because of its Google rating and trade focus: 5.0★ from 53 Google reviews, listed on Google as “HVAC contractor”.

    Based on 6 of 8 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

  14. #14 McKay Mechanical Inc.

    Based in Cornwall

    63/100CR Score

    Ranked #14 because of its Google rating and trade focus: 4.8★ from 51 Google reviews, listed on Google as “HVAC contractor”.

    Based on 6 of 8 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

  15. #15 Noble

    Based in Cornwall

    62/100CR Score

    Ranked #15 because of its Google rating and trade focus: 4.7★ from 38 Google reviews, listed on Google as “HVAC contractor”.

    Based on 6 of 8 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

  16. #16 Marc Viau Mechanical

    Based in Cornwall

    61/100CR Score

    Ranked #16 because of its Google rating and trade focus: 4.4★ from 25 Google reviews, listed on Google as “HVAC contractor”.

    Based on 6 of 8 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 Houde Mechanical Inc

    Based in Cornwall

    60/100CR Score

    Ranked #17 because of its Google rating and trade focus: 4.0★ from 22 Google reviews, listed on Google as “HVAC contractor”.

    Based on 6 of 8 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

  18. #18 Boileau Mechanical Ltd

    Based in Cornwall

    60/100CR Score

    Ranked #18 because of its Google rating and trade focus: 5.0★ from 14 Google reviews, listed on Google as “HVAC contractor”.

    Based on 6 of 8 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

  19. #19 Pat Caron Heating and Air Conditioning | Heating Cornwall

    Based in Cornwall

    60/100CR Score

    Ranked #19 because of its Google rating and trade focus: 4.0★ from 15 Google reviews, listed on Google as “Air conditioning contractor”.

    Based on 6 of 8 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

  20. #20 Energy Wise Builders, LLC

    Based in Massena, 19 km away

    59/100CR Score

    Ranked #20 because of its Google rating and trade focus: 5.0★ from 26 Google reviews, listed on Google as “HVAC contractor”.

    Based on 6 of 8 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

  21. #21 Marleau HVAC Services Ltd

    Based in Cornwall

    59/100CR 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 6 of 8 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

    59/100CR 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 6 of 8 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 Bellatin HVAC

    Based in Cornwall

    58/100CR Score

    Ranked #23 because of its Google rating and trade focus: 5.0★ from 6 Google reviews, listed on Google as “HVAC contractor”.

    Based on 6 of 8 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

  24. #24 Doug Gordon Refrigeration

    Based in Cornwall

    57/100CR Score

    Ranked #24 because of its Google rating and trade focus: 5.0★ from 3 Google reviews, listed on Google as “HVAC contractor”.

    Based on 6 of 8 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

  25. #25 Liberty HVAC Rentals

    Based in Massena, 15 km away

    55/100CR Score

    Ranked #25 because of its Google rating and trade focus: 4.6★ from 5 Google reviews, listed on Google as “HVAC contractor”.

    Based on 6 of 8 factors; credentials and recency not yet collected.

    • 4.6★ from 5 Google reviews
    Hours
    Mon–Fri 8 AM–4:30 PM · Sat–Sun closed
    Address
    33 Stearns St Suite 2, Massena, NY 13662
    View profile for Liberty HVAC Rentals(315) 296-1000

All 27 HVAC contractors by emergency score

#1 to #25 are shown in full above. Here are #26 to #27, in CR Score order; each links to its profile.

HVAC contractors in Cornwall, ranks 26 to 27
RankBusinessCR ScoreGoogle ratingDistance
26Wolseley Plumbing/HVAC/R553.8★ (8)In Cornwall
27Home Services at The Home Depot493.6★ (5)16 km

How we ranked emergency HVAC contractors in Cornwall

Emergency lists move 10 points of the CR Score from reputation to availability: 25% and 20%. Availability credits 24/7 hours, same-day service, weekend hours and weekly open hours. 24/7 HVAC contractors are listed first, then same-day, then the rest; ranks follow that order. Paid placement never changes a rank.

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 from
Reputation25%Bayesian-adjusted Google star rating
Credentials15%Active state license 0.6, bond 0.2, workers’ comp 0.2
Review volume10%log10(reviews + 1) against the list maximum
Recency10%Share of reviews from the last 12 months
Availability20%Weekly open hours, Saturday, Sunday, 24/7 or same-day
Trade focus10%Google main category 1.0, business name 0.7, additional category 0.5
Proximity5%1.0 when based in the city, falling to 0 at the trade’s radius
Completeness5%Website, photos, description, hours, claimed profile (0.2 each)

Emergency HVAC contractors in Cornwall: questions

Which HVAC contractors in Cornwall are open 24/7?

6 on this list post 24/7 hours, including Walker ClimateCare, Superior Plumbing & Heating of Cornwall, SD&G Heating and Cooling, M S Mechanical & Sons and Behemoth Heating and Cooling HVAC Systems.

Who is ranked #1 for emergency heating and cooling in Cornwall, ON?

Walker ClimateCare is #1, with a CR Score of 96 out of 100 on emergency weights.

How are emergency HVAC contractors in Cornwall ranked?

Emergency lists move 10 points of the CR Score from reputation to availability: 25% and 20%. Availability credits 24/7 hours, same-day service, weekend hours and weekly open hours. 24/7 HVAC contractors are listed first, then same-day, then the rest; ranks follow that order. Paid placement never changes a rank.

What should I do before the HVAC contractor arrives?

If you smell gas, leave the building now and call your gas utility or 911 from outside.

How many emergency HVAC contractors here list a phone number?

24 of the 25 businesses ranked in full list a phone number. Tap Call to dial it.

Update log for Cornwall

  1. October 2026: CR Scores recalculated for 27 hvac contractors serving Cornwall.

More emergency and heating and cooling pages