Skip to content
ContractorsRanked

Emergency HVAC Contractors in Ajax, ON (2026)

Top 50 of 573 HVAC contractors, in emergency orderUpdated 0 paid placements in this rankingHow we rank

25 of the 50 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 Ajax: Limcan Certified Heating and Air Conditioning, 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 Ajax at a glance

Top emergency HVAC contractors in Ajax at a glance
RankBusinessCR ScoreGoogle ratingBased inHours
1Limcan Certified Heating and Air Conditioning654.8★ (2,979)Ajax24/7
2Enercare654.8★ (2,085)Ajax24/7
3Enercare654.9★ (8,942)Oshawa, 14 km away24/7
4Reliance Heating, Air Conditioning & Plumbing654.8★ (6,966)Oshawa, 12 km away24/7
5Button's Heating & Air Conditioning654.9★ (1,570)Pickering, 3 km away24/7
6Advantage Airtech ClimateCare644.9★ (1,230)Pickering, 3 km away24/7
7Climate Experts Heating & Cooling Inc.634.9★ (441)Ajax24/7
8Infiniti Home Comfort634.9★ (417)Ajax24/7
9Reliance Heating, Air Conditioning & Plumbing634.9★ (10,870)Richmond Hill, 28 km away24/7
10Mersey Heating and Air Conditioning634.8★ (3,715)Scarborough, 19 km away24/7

Call an emergency HVAC contractor in Ajax 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 50 emergency HVAC contractors in Ajax, ranked

24/7 first, then same-day service, then the rest. Each group is in CR Score order on emergency weights. The full ranking of all 573 is on the HVAC contractors page.

Scores below: based on 8 of 10 factors; credentials and recency not yet collected. Hatched segments mark factors we don't have yet.

  2. #2 Enercare

    Based in Ajax

    65/100CR Score

    Ranked #2 because of its Google rating and trade focus: 4.8★ from 2,085 Google reviews, listed on Google as “HVAC contractor”.

    • 4.8★ from 2,085 Google reviews
    • Open 24/7
    Hours
    Open 24 hours, 7 days
    View profile for Enercare(289) 372-1037

  3. #3 Enercare

    Based in Oshawa, 14 km away

    65/100CR Score

    Ranked #3 because of its Google rating and trade focus: 4.9★ from 8,942 Google reviews, listed on Google as “HVAC contractor”.

    • 4.9★ from 8,942 Google reviews
    • Open 24/7
    Hours
    Open 24 hours, 7 days
    Address
    285 Bloor St W, Oshawa, ON L1J 1R1
    View profile for Enercare(905) 245-2903

  13. #13 Go Lime

    Based in North York, 25 km away

    63/100CR Score

    Ranked #13 because of its Google rating and trade focus: 4.8★ from 6,512 Google reviews, listed on Google as “HVAC contractor”.

    • 4.8★ from 6,512 Google reviews
    • Open 24/7
    Hours
    Open 24 hours, 7 days
    Address
    2225 Sheppard Ave E, North York, ON M2J 5C2
    View profile for Go Lime(877) 747-8292

  15. #15 Lazzaro Gas HVAC

    Based in Ajax

    62/100CR Score

    Ranked #15 because of its Google rating and trade focus: 5.0★ from 140 Google reviews, listed on Google as “HVAC contractor”.

    • 5.0★ from 140 Google reviews
    • Open 24/7
    Hours
    Open 24 hours, 7 days
    Address
    6 Michelle Ct, Whitby, ON L1N 6Z1
    View profile for Lazzaro Gas HVAC(289) 356-2920

  18. #18 AOBUTEC

    Based in Ajax

    61/100CR Score

    Ranked #18 because of its Google rating and trade focus: 4.9★ from 92 Google reviews, listed on Google as “HVAC contractor”.

    • 4.9★ from 92 Google reviews
    • Open 24/7
    Hours
    Open 24 hours, 7 days
    Address
    430 Brock St N, Whitby, ON L1N 4H9
    View profile for AOBUTEC(647) 284-4430

  20. #20 Enercare

    Based in North York, 37 km away

    61/100CR Score

    Ranked #20 because of its Google rating and trade focus: 4.8★ from 11,186 Google reviews, listed on Google as “HVAC contractor”.

    • 4.8★ from 11,186 Google reviews
    • Open 24/7
    Hours
    Open 24 hours, 7 days
    Address
    37 Dufflaw Rd, North York, ON M6A 2W2
    View profile for Enercare(416) 640-1206

  25. #25 Hatco HVAC

    Based in Ajax

    61/100CR Score

    Ranked #25 because of its Google rating and trade focus: 4.9★ from 53 Google reviews, listed on Google as “HVAC contractor”.

    • 4.9★ from 53 Google reviews
    • Open 24/7
    Hours
    Open 24 hours, 7 days
    View profile for Hatco HVAC(416) 528-8967

Top 50 of 573 HVAC contractors by emergency score

#1 to #25 are shown in full above. Here are #26 to #50, in CR Score order; each links to its profile.

HVAC contractors in Ajax, ranks 26 to 50
RankBusinessCR ScoreGoogle ratingDistance
26J Squared HVAC615.0★ (49)In Ajax
27ICare Home Comfort614.9★ (836)24 km
28Ashton Heating & Cooling604.9★ (512)22 km
29Sharpe Advantage Heating And Air Conditioning605.0★ (96)9 km
30Daly Home Comfort605.0★ (247)19 km
31Max Mechanical - Heating & Air Conditioning604.8★ (34)In Ajax
32Climax Heating & Air Conditioning - Condo HVAC Service604.9★ (529)25 km
33Urban Life Heating & Cooling INC.604.9★ (42)5 km
34Constant Home Comfort604.8★ (583)25 km
35Service Express HVAC604.9★ (384)24 km
36ThermEnergy heating and cooling Ajax605.0★ (21)In Ajax
37Hargrave Heating & Air Conditioning594.9★ (366)24 km
38Joe's Heating and Air Conditioning594.9★ (725)30 km
39BreezeCome Home Service/Quality Breeze 清风到家 服务到家594.8★ (481)25 km
40Enercare594.7★ (1,470)31 km
41Superior Care Home Services Inc.595.0★ (266)24 km
42Venus air595.0★ (19)In Ajax
43HI TECH HOME COMFORT HEATING COOLING594.7★ (22)In Ajax
44Smile HVAC595.0★ (1,314)38 km
45AccuServ Heating and Air Conditioning594.9★ (490)29 km
46Aire One Heating & Cooling594.8★ (480)26 km
47Summers and Smith Cooling & Heating Limited594.9★ (1,559)38 km
48Reliance Heating, Air Conditioning & Plumbing594.7★ (1,854)35 km
49City Home Comfort594.7★ (697)28 km
50Econoair Heating & Cooling Inc594.9★ (435)29 km

How we ranked emergency HVAC contractors in Ajax

Emergency lists move 10 points of the CR Score from reputation to availability: 15% and 15%. 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
Reputation15%Google star rating, adjusted for how many reviews back it
Credentials15%Active state license, bond and workers’ comp on file
Review volume10%Number of Google reviews, compared with the most-reviewed business on the list
Recency5%Share of reviews from the last 12 months
Availability15%Weekly open hours, Saturday, Sunday, 24/7 or same-day
Trade focus10%How clearly the business does this trade (its Google category and name)
Proximity5%Based in the city scores highest, less the farther away it is
Claimed profile10%The business has claimed its ContractorsRanked profile (free or paid earn the same)
Partnered5%The business links to ContractorsRanked from its own website with our badge, checked periodically
ContractorsRanked reviews10%Verified customer reviews collected by ContractorsRanked: their rating and how many there are

Emergency HVAC contractors in Ajax: questions

Which HVAC contractors in Ajax are open 24/7?

25 on this list post 24/7 hours, including Limcan Certified Heating and Air Conditioning, Enercare, Enercare, Reliance Heating, Air Conditioning & Plumbing and Button's Heating & Air Conditioning.

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

Limcan Certified Heating and Air Conditioning is #1, with a CR Score of 65 out of 100 on emergency weights.

How are emergency HVAC contractors in Ajax ranked?

Emergency lists move 10 points of the CR Score from reputation to availability: 15% and 15%. 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?

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

Update log for Ajax

  1. October 2026: CR Scores recalculated for 573 hvac contractors serving Ajax.
  2. October 2026: 3 duplicate listings merged.

More emergency and heating and cooling pages