249 HVAC contractors ranked by CR ScoreUpdated 0 paid placements in this rankingHow we rank →
Best overall in Waterloo: Aire One Heating & Cooling KW, CR Score 95/100; 4.8★ from 9,448 Google reviews; open 24/7.
Best for emergencies (open 24/7): Able Air Conditioning & Heating, posts 24/7 hours; ranked #2 of 249.
Most-reviewed: Reliance Heating, Air Conditioning & Plumbing, 9,230 Google reviews at 4.7★, the most of 249 ranked after Aire One Heating & Cooling KW; ranked #10.
Rankings can't be bought. Contractors can't pay to change their rank or score. How we rank
249 Waterloo HVAC contractors are ranked here by CR Score, from 8 published factors. 107 are open 24/7, 147 open Saturdays and 128 open Sundays, based on posted hours. The median Google rating is 4.9★ across 249 rated businesses.
| Rank | Business | CR Score | Google rating | Based in | Hours | Best for |
|---|---|---|---|---|---|---|
| 1 | Aire One Heating & Cooling KW | 95 | 4.8★ (9,448) | Kitchener, 5 km away | 24/7 | Overall |
| 2 | Able Air Conditioning & Heating | 93 | 5.0★ (1,247) | Kitchener, 6 km away | 24/7 | Emergencies |
| 3 | Local Heating And Cooling | 93 | 5.0★ (397) | Waterloo | 24/7 | — |
| 4 | Reliance Heating, Air Conditioning & Plumbing | 93 | 4.7★ (2,268) | Waterloo | 24/7 | — |
| 5 | Delta Air Systems Ltd. | 92 | 4.9★ (631) | Waterloo | 24/7 | — |
| 6 | Total Aire Care Inc. | 92 | 5.0★ (857) | Kitchener, 9 km away | 24/7 | — |
| 7 | LG Home Comfort KWC | 92 | 4.9★ (674) | Kitchener, 6 km away | 24/7 | — |
| 8 | Advance Heating & Cooling KW | 91 | 5.0★ (451) | Kitchener, 8 km away | 24/7 | — |
| 9 | Dunn Heating and Air Conditioning | 91 | 4.7★ (969) | Waterloo | 24/7 | — |
| 10 | Reliance Heating, Air Conditioning & Plumbing | 91 | 4.7★ (9,230) | Cambridge, 19 km away | 24/7 | Most reviews |
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.
Ranked #1 because of its Google rating and review volume: 4.8★ from 9,448 Google reviews, the most Google reviews on this list (9,448).
Based in Kitchener, 6 km away
Ranked #2 because of its Google rating and availability: 5.0★ from 1,247 Google reviews, open 24/7.
Based in Waterloo
Ranked #3 because of its Google rating and availability: 5.0★ from 397 Google reviews, open 24/7.
Based in Waterloo
Ranked #4 because of its Google rating and availability: 4.7★ from 2,268 Google reviews, open 24/7.
Based in Waterloo
Ranked #5 because of its Google rating and availability: 4.9★ from 631 Google reviews, open 24/7.
Based in Kitchener, 9 km away
Ranked #6 because of its Google rating and availability: 5.0★ from 857 Google reviews, open 24/7.
Based in Kitchener, 6 km away
Ranked #7 because of its Google rating and availability: 4.9★ from 674 Google reviews, open 24/7.
Based in Kitchener, 8 km away
Ranked #8 because of its Google rating and availability: 5.0★ from 451 Google reviews, open 24/7.
Based in Waterloo
Ranked #9 because of its Google rating and availability: 4.7★ from 969 Google reviews, open 24/7.
Based in Cambridge, 19 km away
Ranked #10 because of its Google rating and availability: 4.7★ from 9,230 Google reviews, open 24/7.
Based in Cambridge, 18 km away
Ranked #11 because of its Google rating and availability: 4.9★ from 2,155 Google reviews, open 24/7.
Based in Kitchener, 5 km away
Ranked #12 because of its Google rating and availability: 4.9★ from 447 Google reviews, open 24/7.
Based in Cambridge, 12 km away
Ranked #13 because of its Google rating and availability: 4.8★ from 1,534 Google reviews, open 24/7.
Based in Kitchener, 8 km away
Ranked #14 because of its Google rating and availability: 4.9★ from 378 Google reviews, open 24/7.
Based in Kitchener, 10 km away
Ranked #15 because of its Google rating and availability: 5.0★ from 233 Google reviews, open 24/7.
Based in Kitchener, 3 km away
Ranked #16 because of its Google rating and availability: 4.9★ from 187 Google reviews, open 24/7.
Based in Kitchener, 9 km away
Ranked #17 because of its Google rating and availability: 5.0★ from 203 Google reviews, open 24/7.
Based in Huron East, 8 km away
Ranked #18 because of its Google rating and availability: 4.9★ from 268 Google reviews, open 24/7.
Based in Brant, 18 km away
Ranked #19 because of its Google rating and availability: 4.9★ from 593 Google reviews, open 24/7.
Based in Kitchener, 3 km away
Ranked #20 because of its Google rating and availability: 4.9★ from 132 Google reviews, open 24/7.
Based in Kitchener, 4 km away
Ranked #21 because of its Google rating and availability: 4.9★ from 120 Google reviews, open 24/7.
Based in Kitchener, 3 km away
Ranked #22 because of its Google rating and availability: 4.9★ from 109 Google reviews, open 24/7.
Based in Waterloo
Ranked #23 because of its Google rating and availability: 5.0★ from 59 Google reviews, open 24/7.
Based in Waterloo
Ranked #24 because of its Google rating and trade focus: 4.9★ from 525 Google reviews, listed on Google as “HVAC contractor”.
Based in Cambridge, 12 km away
Ranked #25 because of its Google rating and availability: 4.6★ from 1,022 Google reviews, open 24/7.
#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 249 ranked HVAC contractors here; the rest are on their profiles.
20 more HVAC contractors within 40 km that we can't rank yet: too few reviews, or a trade we couldn't confirm. Listed A to Z.
| Business | Google rating | Distance |
|---|---|---|
| Action Air Conditioning And Refrigeration Inc (Since 1978) | 5.0★ (1) | In Waterloo |
| Ariss Duct Mechanical | 5.0★ (2) | 27 km |
| Arktic HVAC Services | Kitchener | In Waterloo | |
| Assurance Heating and Cooling | 4.9★ (87) | 24 km |
| Bradley Heating and Cooling | 3.0★ (2) | 6 km |
| Capital Plumbing & Heating | 1.0★ (1) | 4 km |
| Guelph ClimateCare | 4.7★ (164) | 22 km |
| Jess-Don Dunford Ltd | 5.0★ (2) | 25 km |
| Macker Mechanical | 5.0★ (2) | 15 km |
| Mason Mechanical Services Inc | 5.0★ (2) | 10 km |
| moe Heating & Air Conditioning Systems | 5.0★ (12) | 7 km |
| Mr HVAC Services | 5.0★ (2) | 17 km |
| NRG HVAC | 5.0★ (2) | In Waterloo |
| Radcliffe Service Inc | 5.0★ (2) | 34 km |
| Smith and Long Limited | 5.0★ (1) | 3 km |
| Startek Building Solutions | 5.0★ (1) | 3 km |
| Ultra Plumbing & HVAC | 5.0★ (15) | 7 km |
| Ventilation HVAC Kitchener | 5.0★ (2) | 5 km |
| Watson Mechanical Contractors | 5.0★ (2) | 19 km |
| WinterHeat Rescue HVAC | 5.0★ (2) | In Waterloo |
US national ranges converted to CAD, not adjusted for Waterloo. Each row names its basis and the month we checked it.
| Job | Low | Typical | High | Basis | Checked |
|---|---|---|---|---|---|
| AC replacement | CA$5,460 | CA$8,400 | CA$11,350 | Per system, installed (unit plus labor); typical range of customer-reported jobs. US national range converted at 1.4054 CAD per USD (Bank of Canada, October 20, 2026) | October 2026 |
| Furnace replacement | CA$3,970 | CA$6,770 | CA$9,690 | Per system, installed; typical range of customer-reported jobs. US national range converted at 1.4054 CAD per USD (Bank of Canada, October 20, 2026) | October 2026 |
In Ontario, 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.
We scored 249 Waterloo 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.
| Factor | Weight | Computed from | In Waterloo data |
|---|---|---|---|
| Reputation | 35% | Bayesian-adjusted Google star rating | Measured |
| Credentials | 15% | Active state license 0.6, bond 0.2, workers’ comp 0.2 | Not yet collected |
| Review volume | 10% | log10(reviews + 1) against the list maximum | Measured |
| Recency | 10% | Share of reviews from the last 12 months | Not yet collected |
| Availability | 10% | Weekly open hours, Saturday, Sunday, 24/7 or same-day | Measured |
| Trade focus | 10% | Google main category 1.0, business name 0.7, additional category 0.5 | Measured |
| Proximity | 5% | 1.0 when based in the city, falling to 0 at the trade’s radius | Measured |
| Completeness | 5% | Website, photos, description, hours, claimed profile (0.2 each) | Measured |