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Emergency HVAC Contractors in Marengo, IL (2026)

Top 50 of 344 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 Marengo: Black Diamond Plumbing & Mechanical Inc., 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 Marengo at a glance

Top emergency HVAC contractors in Marengo at a glance
RankBusinessCR ScoreGoogle ratingBased inHours
1Black Diamond Plumbing & Mechanical Inc.644.9★ (6,580)McHenry, 17 mi away24/7
2Woodstock Heating, Cooling & Electrical644.9★ (1,222)Woodstock, 10 mi away24/7
3GSHA Services, LTD634.9★ (747)Woodstock, 10 mi away24/7
4G & R Heating and Air624.8★ (2,067)Gilberts, 16 mi away24/7
5Lifeline Plumbing, Heating & Cooling624.9★ (3,222)Elgin, 20 mi away24/7
624HR Home Comfort Services624.9★ (1,374)Lake in the Hills, 17 mi away24/7
7Climate Control Services LLC615.0★ (776)Elgin, 18 mi away24/7
8Althoff Home Services614.8★ (1,043)Crystal Lake, 17 mi away24/7
9Legacy Home Services614.9★ (571)Crystal Lake, 15 mi away24/7
10Leith Heating and Cooling Inc.615.0★ (784)Elgin, 18 mi away24/7

Call an emergency HVAC contractor in Marengo 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 Marengo, 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 344 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.

  3. #3 GSHA Services, LTD

    Based in Woodstock, 10 mi away

    63/100CR Score

    Ranked #3 because of its Google rating and trade focus: 4.9★ from 747 Google reviews, listed on Google as “HVAC contractor”.

    • 4.9★ from 747 Google reviews
    • Open 24/7
    Hours
    Open 24 hours, 7 days
    Address
    1257 Cobblestone Way Unit A, Woodstock, IL 60098
    View profile for GSHA Services, LTD(224) 220-3660

  4. #4 G & R Heating and Air

    Based in Gilberts, 16 mi away

    62/100CR Score

    Ranked #4 because of its Google rating and trade focus: 4.8★ from 2,067 Google reviews, listed on Google as “HVAC contractor”.

    • 4.8★ from 2,067 Google reviews
    • Open 24/7
    Hours
    Open 24 hours, 7 days
    Address
    24 Center Dr Unit #9, Gilberts, IL 60136
    View profile for G & R Heating and Air(224) 850-3187

  8. #8 Althoff Home Services

    Based in Crystal Lake, 17 mi away

    61/100CR Score

    Ranked #8 because of its Google rating and trade focus: 4.8★ from 1,043 Google reviews, listed on Google as “HVAC contractor”.

    • 4.8★ from 1,043 Google reviews
    • Open 24/7
    Hours
    Open 24 hours, 7 days
    Address
    8001 S Illinois Rte 31, Crystal Lake, IL 60014
    View profile for Althoff Home Services(815) 455-7000

  9. #9 Legacy Home Services

    Based in Crystal Lake, 15 mi away

    61/100CR Score

    Ranked #9 because of its Google rating and trade focus: 4.9★ from 571 Google reviews, listed on Google as “HVAC contractor”.

    • 4.9★ from 571 Google reviews
    • Open 24/7
    Hours
    Open 24 hours, 7 days
    Address
    7316 Teckler Blvd Ste 2B, Crystal Lake, IL 60014
    View profile for Legacy Home Services(815) 938-0137

  16. #16 CKA Mechanical Inc.

    Based in Hampshire, 12 mi away

    60/100CR Score

    Ranked #16 because of its Google rating and trade focus: 5.0★ from 153 Google reviews, listed on Google as “HVAC contractor”.

    • 5.0★ from 153 Google reviews
    • Open 24/7
    Hours
    Open 24 hours, 7 days
    Address
    982 S State St, Hampshire, IL 60140
    View profile for CKA Mechanical Inc.(224) 218-1060

  19. #19 Absolute Comfort

    Based in Crystal Lake, 15 mi away

    60/100CR Score

    Ranked #19 because of its Google rating and trade focus: 4.8★ from 250 Google reviews, listed on Google as “HVAC contractor”.

    • 4.8★ from 250 Google reviews
    • Open 24/7
    Hours
    Open 24 hours, 7 days
    Address
    60 W Terra Cotta Ave, Crystal Lake, IL 60014
    View profile for Absolute Comfort(815) 893-9276

  21. #21 Amy Home Services

    Based in Carpentersville, 19 mi away

    60/100CR Score

    Ranked #21 because of its Google rating and trade focus: 4.8★ from 483 Google reviews, listed on Google as “HVAC contractor”.

    • 4.8★ from 483 Google reviews
    • Open 24/7
    Hours
    Open 24 hours, 7 days
    Address
    39 N Western Ave, Carpentersville, IL 60110
    View profile for Amy Home Services(847) 239-5771

Top 50 of 344 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 Marengo, ranks 26 to 50
RankBusinessCR ScoreGoogle ratingDistance
26Perfect Temp Heating & Cooling594.8★ (719)23 mi
27McNally's Heating and Cooling595.0★ (116)15 mi
28Air Blue Heating and Cooling595.0★ (148)17 mi
29Smith-Dahlquist, Inc.594.9★ (194)18 mi
30JV heating & cooling LLC594.8★ (69)11 mi
31Assured Appliance & Heating & Air594.8★ (62)11 mi
32Combined Services HVAC594.8★ (175)17 mi
33Comfort Air Heating & Cooling Inc594.7★ (185)16 mi
34Hurst Heating & Cooling594.8★ (463)23 mi
35Arctic Heating & Cooling594.9★ (102)16 mi
36Wally's Heating & AC594.9★ (95)15 mi
37Half Price Heating & Air594.7★ (75)12 mi
38Alex Quality Services585.0★ (101)17 mi
39Northern Continental Heating & Cooling, Inc.584.8★ (125)16 mi
40Birdie Heating & Cooling585.0★ (121)19 mi
41Premier Comfort Heating & Cooling LLC584.9★ (371)24 mi
42Andrews heating and air inc584.9★ (36)11 mi
43Northern Comfort Heating Air Conditioning Duct Cleaning,Inc584.9★ (240)22 mi
44One Call Heating & Cooling585.0★ (138)20 mi
45Gleason Plumbing, Heating and Air584.8★ (420)24 mi
46Algonquin Heating & Air Conditioning584.7★ (143)17 mi
47Cady Heating and Cooling584.8★ (128)18 mi
48Bear Necessities Home Services585.0★ (174)23 mi
49Evolution Mechanical Heating & Cooling585.0★ (57)16 mi
50Woodstock Heating and Cooling, LLC585.0★ (45)15 mi

How we ranked emergency HVAC contractors in Marengo

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 Marengo: questions

Which HVAC contractors in Marengo are open 24/7?

25 on this list post 24/7 hours, including Black Diamond Plumbing & Mechanical Inc., Woodstock Heating, Cooling & Electrical, GSHA Services, LTD, G & R Heating and Air and Lifeline Plumbing, Heating & Cooling.

Who is ranked #1 for emergency heating and cooling in Marengo, IL?

Black Diamond Plumbing & Mechanical Inc. is #1, with a CR Score of 64 out of 100 on emergency weights.

How are emergency HVAC contractors in Marengo 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 Marengo

  1. October 2026: CR Scores recalculated for 344 hvac contractors serving Marengo.
  2. October 2026: 4 duplicate listings merged.

More emergency and heating and cooling pages