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ContractorsRanked

Best HVAC Contractors in Harvard, IL (2026)

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

The short answer

  1. 1

    Best overall in Harvard: Black Diamond Plumbing & Mechanical Inc., CR Score 92/100; 4.9★ from 6,580 Google reviews; open 24/7.

  2. 2

    Best for emergencies (open 24/7): Woodstock Heating, Cooling & Electrical, posts 24/7 hours; ranked #2 of 235.

  3. 26

    Most-reviewed: Appliance Repair Experts, 1,444 Google reviews at 4.8★, the most of 235 ranked after Black Diamond Plumbing & Mechanical Inc.; ranked #26.

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

235 Harvard HVAC contractors are ranked here by CR Score, from 8 published factors. 111 are open 24/7, 165 open Saturdays and 136 open Sundays, based on posted hours. The median Google rating is 4.9★ across 235 rated businesses.

Top 10 HVAC contractors in Harvard at a glance

Top 10 HVAC contractors in Harvard at a glance
RankBusinessCR ScoreGoogle ratingBased inHoursBest for
1Black Diamond Plumbing & Mechanical Inc.924.9★ (6,580)McHenry, 18 mi away24/7Overall
2Woodstock Heating, Cooling & Electrical914.9★ (1,222)Woodstock, 11 mi away24/7Emergencies
3GSHA Services, LTD904.9★ (747)Woodstock, 13 mi away24/7—
424HR Home Comfort Services884.9★ (1,374)Lake in the Hills, 23 mi away24/7—
5Master Services Inc.884.7★ (976)Lake Geneva, 15 mi away24/7—
6McHenry Heating & Air, Inc.884.9★ (596)McHenry, 19 mi away24/7—
7H. J. Faust, Inc. Heating and Air Conditioning884.9★ (1,340)Burlington, 24 mi away24/7—
8Legacy Home Services874.9★ (571)Crystal Lake, 20 mi away24/7—
9Rellaire Smart Home Systems874.9★ (472)Crystal Lake, 21 mi away24/7—
10WeatherWise Heating & AC repair874.8★ (744)Crystal Lake, 20 mi away24/7—

The 235 best HVAC contractors in Harvard, ranked

Ordered by CR Score, a 0–100 score from 8 published factors. Paid placement never changes the order.

Scores below: based on 6 of 8 factors; credentials and recency not yet collected. Hatched segments mark factors we don't have yet.

  3. #3 GSHA Services, LTD

    Based in Woodstock, 13 mi away

    90/100CR Score

    Ranked #3 because of its Google rating and availability: 4.9★ from 747 Google reviews, open 24/7.

    • 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

  21. #21 Absolute Comfort

    Based in Crystal Lake, 19 mi away

    86/100CR Score

    Ranked #21 because of its Google rating and availability: 4.8★ from 250 Google reviews, open 24/7.

    • 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

HVAC contractors ranked #26 to #50

#1 to #25 are shown in full above. Here are #26 to #50, in CR Score order; each links to its profile. We publish the top 50 of 235 ranked HVAC contractors here; the rest are on their profiles.

HVAC contractors in Harvard, ranks 26 to 50
RankBusinessCR ScoreGoogle ratingDistance
26Appliance Repair Experts854.8★ (1,444)13 mi
27Bear Necessities Home Services855.0★ (174)24 mi
28CKA Mechanical Inc.855.0★ (153)23 mi
29Air Blue Heating and Cooling855.0★ (148)24 mi
30Bob's Refrigeration heating and air conditioning inc854.6★ (9)3 mi
31Arctic Heating & Cooling854.9★ (102)20 mi
32Broadway Heating and Cooling LLC845.0★ (33)16 mi
33Wally's Heating & AC844.9★ (95)21 mi
34Alex Quality Services845.0★ (101)24 mi
35Hudak Heating & Air Conditioning845.0★ (16)12 mi
36South Shore Heating & Air Conditioning Inc.845.0★ (104)25 mi
37Duane Blanton Plumbing, Sewer, Heating & Cooling844.9★ (105)23 mi
38Evolution Mechanical Heating & Cooling845.0★ (57)21 mi
39Northern Continental Heating & Cooling, Inc.844.8★ (125)22 mi
40Woodstock Heating and Cooling, LLC845.0★ (45)20 mi
41Air Solutions844.9★ (931)24 mi
42Absolute Value Heating & Cooling - Rockford844.9★ (85)23 mi
43American Comfort Central844.8★ (50)18 mi
44C&C Heating & Air Conditioning834.7★ (28)14 mi
45Optimized Air835.0★ (72)24 mi
46Alex’s Duct Cleaning835.0★ (269)21 mi
47Andrews heating and air inc834.9★ (36)19 mi
48Breeze Heating and AC LLC835.0★ (32)20 mi
49CVC HVAC - Heating & Cooling835.0★ (9)In Harvard
50A Plus HVAC LLC834.6★ (10)11 mi

Also serving Harvard

20 more HVAC contractors within 25 mi that we can't rank yet: too few reviews, or a trade we couldn't confirm. Listed A to Z.

Unranked HVAC contractors serving Harvard
BusinessGoogle ratingDistance
5 Start Plumbing Heating & Cooling3.0★ (2)25 mi
A & J General5.0★ (2)21 mi
A Hartlett & Son4.5★ (2)11 mi
Air Management Services Inc4.0★ (2)In Harvard
Algonquin Heating & Air Conditioning4.7★ (143)24 mi
Anthonys Heating & Air3.0★ (2)24 mi
Bill's Heating and Cooling Service5.0★ (2)23 mi
Conservative Heating & Air Conditioning3.0★ (2)25 mi
D & D Comfort Inc. Heating & Air Conditioning, Inc.4.9★ (110)21 mi
Dad And Son LLC5.0★ (2)13 mi
Dowe & Wagner Inc. Powered by Legacy Home Services4.4★ (107)16 mi
Eagle Refrigeration Service4.5★ (2)16 mi
Hartwig Plumbing & Heating5.0★ (1)In Harvard
Home Services at The Home Depot4.5★ (2)16 mi
Magic HVAC Inc5.0★ (2)23 mi
Nick's Action Air5.0★ (2)22 mi
One Call Heating & Cooling5.0★ (2)24 mi
Service Concepts Inc - Commercial Heating and Cooling - Genoa, IL3.0★ (2)23 mi
Signature HVAC/DUCT CleaningIn Harvard
ZN Heating and Cooling, Inc5.0★ (2)23 mi

How much do HVAC contractors cost in Harvard?

National price ranges in USD, not adjusted for Harvard. Each row names its basis and the month we checked it.

How much do HVAC contractors cost in Harvard?
JobLowTypicalHighBasisChecked
AC replacement$3,887$5,978$8,073Per system, installed (unit plus labor); typical range of customer-reported jobs. US national rangeOctober 2026
Furnace replacement$2,823$4,814$6,896Per system, installed; typical range of customer-reported jobs. US national rangeOctober 2026

When to hire an HVAC contractor in Illinois

In Illinois, 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 Harvard HVAC contractors

We scored 235 Harvard HVAC contractors on 8 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. Unknown factors are left out of the score, 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 Harvard data
Reputation35%Bayesian-adjusted Google star ratingMeasured
Credentials15%Active state license 0.6, bond 0.2, workers’ comp 0.2Not yet collected
Review volume10%log10(reviews + 1) against the list maximumMeasured
Recency10%Share of reviews from the last 12 monthsNot yet collected
Availability10%Weekly open hours, Saturday, Sunday, 24/7 or same-dayMeasured
Trade focus10%Google main category 1.0, business name 0.7, additional category 0.5Measured
Proximity5%1.0 when based in the city, falling to 0 at the trade’s radiusMeasured
Completeness5%Website, photos, description, hours, claimed profile (0.2 each)Measured

HVAC contractors in Harvard: frequently asked questions

Who is the best HVAC contractor in Harvard?

By CR Score, the highest-ranked HVAC contractor in Harvard, IL is Black Diamond Plumbing & Mechanical Inc. with a CR Score of 92/100. It has 4.9★ from 6,580 Google reviews. It is open 24/7. Woodstock Heating, Cooling & Electrical (#2) and GSHA Services, LTD (#3) follow. We ranked 235 HVAC contractors on 8 factors, last updated October 22, 2026.

How many HVAC contractors are there in Harvard?

ContractorsRanked ranks 235 HVAC contractors serving Harvard, IL. 1 of them is based in Harvard; the rest serve it from nearby towns. Another 20 within 25 mi are listed but not ranked yet. Counts are as of October 2026.

Which HVAC contractors in Harvard are open 24/7?

111 ranked HVAC contractors in Harvard post 24/7 hours. The highest-ranked are Black Diamond Plumbing & Mechanical Inc. (#1), Woodstock Heating, Cooling & Electrical (#2) and GSHA Services, LTD (#3). Hours come from each business's Google listing as of October 2026, so call to confirm.

Which HVAC contractors in Harvard work on weekends?

165 of 235 ranked HVAC contractors post Saturday hours and 136 post Sunday hours. The highest-ranked open Saturdays are Black Diamond Plumbing & Mechanical Inc. (#1), Woodstock Heating, Cooling & Electrical (#2) and GSHA Services, LTD (#3). Posted hours are office hours; crews may book weekend jobs separately.

How much does ac replacement cost in Harvard?

AC replacement typically costs $3,887 to $8,073, with $5,978 typical (Per system, installed (unit plus labor); typical range of customer-reported jobs. US national range). This is a national range, not adjusted for Harvard. Prices were last checked October 2026. Get at least two written quotes before you hire.

What Google rating do Harvard HVAC contractors have?

The median Google rating among 235 rated HVAC contractors in Harvard is 4.9★, with a median of 24 reviews. Black Diamond Plumbing & Mechanical Inc. has the most, 6,580 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 Harvard?

In Illinois, 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 8 published factors, led by reputation (35%), credentials (15%), review volume (10%) and recency (10%). Factors we cannot measure are left out, not scored as zero. Only businesses with a confirmed trade and 3 or more reviews, or a claimed profile, are ranked.

Update log for Harvard

  1. October 2026: CR Scores recalculated for 235 hvac contractors serving Harvard.
  2. October 2026: 5 duplicate listings merged.

More HVAC contractors and Harvard pages

Other trades in Harvard