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Emergency HVAC Contractors in London, ON (2026)

Top 50 of 129 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 London: Reliance London Heating, Air Conditioning & Plumbing, 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 London at a glance

Top emergency HVAC contractors in London at a glance
RankBusinessCR ScoreGoogle ratingBased inHours
1Reliance London Heating, Air Conditioning & Plumbing684.8★ (12,217)London24/7
2Roy Inch & Sons Home Services by Enercare654.7★ (1,490)London24/7
3M & K Heating and Air Conditioning654.6★ (1,614)London24/7
4Handy Bros. HVAC London (AC and Furnace Repair)644.9★ (536)London24/7
5Salliss Plumbing & Heating634.8★ (271)London24/7
6Orzech Heating and Cooling634.8★ (272)London24/7
7Hawana HVAC Solutions Same Day Furnace & Installation635.0★ (130)London24/7
8Superior Plumbing & Heating of London624.6★ (250)London24/7
9Presto Home Service614.9★ (71)London24/7
10Air Design Services Heating & Cooling614.9★ (62)London24/7

Call an emergency HVAC contractor in London 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 London, 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 129 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.

  11. #11 Aire One

    Based in London

    61/100CR Score

    Ranked #11 because of its Google rating and trade focus: 4.4★ from 177 Google reviews, listed on Google as “HVAC contractor”.

    • 4.4★ from 177 Google reviews
    • Open 24/7
    Hours
    Open 24 hours, 7 days
    Address
    878 Wellington Rd, London, ON N6E 1L9
    View profile for Aire One(519) 668-3000

  13. #13 Abode Home Comfort

    Based in St. Thomas, 23 km away

    61/100CR Score

    Ranked #13 because of its Google rating and trade focus: 5.0★ from 499 Google reviews, listed on Google as “HVAC contractor”.

    • 5.0★ from 499 Google reviews
    • Open 24/7
    Hours
    Open 24 hours, 7 days
    Address
    107 Gaylord Rd, St Thomas, ON N5P 3S3
    View profile for Abode Home Comfort(519) 953-4821

  20. #20 All Climate Inc.

    Based in London

    60/100CR Score

    Ranked #20 because of its Google rating and trade focus: 4.8★ from 23 Google reviews, listed on Google as “HVAC contractor”.

    • 4.8★ from 23 Google reviews
    • Open 24/7
    Hours
    Open 24 hours, 7 days
    Address
    1674 Hamilton Rd, London, ON N6M 1G4
    View profile for All Climate Inc.(519) 318-0949

Top 50 of 129 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 London, ranks 26 to 50
RankBusinessCR ScoreGoogle ratingDistance
26MKM MECHANICAL LIMITED595.0★ (14)In London
27Enns Air - HVAC Services595.0★ (110)20 km
28London Home Comfort594.7★ (13)In London
29Mozee Gas Heating & Cooling595.0★ (11)In London
30Royal Air Conditioning & Heating Ltd.594.7★ (13)In London
31KALJIC Mechanical595.0★ (55)17 km
32DHVAC REFRIGERATION OF CANADA, MECHANICAL, HEATING & REFRIGERATION SYSTEM584.5★ (8)In London
33Getec Home Comfort585.0★ (6)In London
34Tiger Temp585.0★ (6)In London
35HVAC Trust Heating & Cooling585.0★ (5)In London
36Poulsen583.3★ (16)In London
37Budget Heating & Cooling584.9★ (14)8 km
38MDR Hvac , London Heating and Air Conditioning Services585.0★ (7)4 km
39Desna Heating & Cooling585.0★ (4)In London
40M & R Mechanical Heating & Cooling585.0★ (4)In London
41Superior Plumbing & Heating of St. Thomas574.6★ (73)In London
42Hybrid Comfort Systems Inc O/A Resource Trades Group575.0★ (28)In London
43Premier Gas Services575.0★ (53)30 km
44Hurn Plumbing and Heating564.9★ (23)23 km
45AJM Heating Air Conditioning & Gas Services Inc.564.8★ (36)28 km
46Royal 1 HVAC Services565.0★ (5)13 km
47AirWise Heating & Cooling565.0★ (29)30 km
48Steve Young Plumbing & Heating Ltd554.8★ (83)16 km
49Superior Plumbing & Heating of Ingersoll554.5★ (19)29 km
50The Public Servant545.0★ (31)In London

How we ranked emergency HVAC contractors in London

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 London: questions

Which HVAC contractors in London are open 24/7?

25 on this list post 24/7 hours, including Reliance London Heating, Air Conditioning & Plumbing, Roy Inch & Sons Home Services by Enercare, M & K Heating and Air Conditioning, Handy Bros. HVAC London (AC and Furnace Repair) and Salliss Plumbing & Heating.

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

Reliance London Heating, Air Conditioning & Plumbing is #1, with a CR Score of 68 out of 100 on emergency weights.

How are emergency HVAC contractors in London 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 London

  1. October 2026: CR Scores recalculated for 129 hvac contractors serving London.

More emergency and heating and cooling pages