7 HVAC contractors ranked by CR ScoreUpdated 0 paid placements in this rankingHow we rank →
Best overall in Denison: Siemer Plumbing & Heating Inc, CR Score 57/100; 3.8★ from 6 Google reviews; open Sundays until 8 PM.
Most-reviewed: Knobbe Plumbing & HVAC, 13 Google reviews at 4.5★, the most of 7 ranked; ranked #4.
Rankings can't be bought. Contractors can't pay to change their rank or score. How we rank
7 Denison HVAC contractors are ranked here by CR Score, from ten published factors. 1 open Saturdays and 1 open Sundays, based on posted hours. The median Google rating is 3.9★ across 7 rated businesses.
| Rank | Business | CR Score | Google rating | Based in | Hours | Best for |
|---|---|---|---|---|---|---|
| 1 | Siemer Plumbing & Heating Inc | 57 | 3.8★ (6) | Denison | Sun · Evenings | Overall |
| 2 | Granzen Plumbing & Heating | 54 | 4.8★ (6) | Denison | — | — |
| 3 | Camblin Plumbing & Heating Inc | 51 | 3.2★ (9) | Harlan, 25 mi away | — | — |
| 4 | Knobbe Plumbing & HVAC | 50 | 4.5★ (13) | Carroll, 25 mi away | Sat | Most reviews |
| 5 | Scheck's Plumbing & Heating | 47 | 3.9★ (7) | Carroll, 24 mi away | — | — |
| 6 | Haberl Plumbing & Heating | 47 | 4.0★ (6) | Carroll, 22 mi away | — | — |
| 7 | Bruck Plumbing & Heating | 42 | 3.7★ (3) | Harlan, 25 mi away | — | — |
Ordered by CR Score, a 0–100 score from ten published factors. Paid placement never changes the order.
Ranked #1 because of its Google rating and trade focus: 3.8★ from 6 Google reviews, listed on Google as “Air conditioning contractor”.
Based on 8 of 10 factors; credentials and recency not yet collected.
Based in Denison
Ranked #2 because of its Google rating and review volume: 4.8★ from 6 Google reviews.
Based on 7 of 10 factors; credentials, recency and availability not yet collected.
Based in Harlan, 25 mi away
Ranked #3 because of its Google rating and trade focus: 3.2★ from 9 Google reviews, listed on Google as “Heating contractor”.
Based on 7 of 10 factors; credentials, recency and availability not yet collected.
Based in Carroll, 25 mi away
Ranked #4 because of its Google rating and review volume: 4.5★ from 13 Google reviews, the most in Denison.
Based on 8 of 10 factors; credentials and recency not yet collected.
Based in Carroll, 24 mi away
Ranked #5 because of its Google rating and review volume: 3.9★ from 7 Google reviews.
Based on 7 of 10 factors; credentials, recency and availability not yet collected.
Based in Carroll, 22 mi away
Ranked #6 because of its Google rating and review volume: 4.0★ from 6 Google reviews.
Based on 7 of 10 factors; credentials, recency and availability not yet collected.
Based in Harlan, 25 mi away
Ranked #7 because of its Google rating and trade focus: 3.7★ from 3 Google reviews, listed on Google as “Plumber”.
Based on 8 of 10 factors; credentials and recency not yet collected.
National price ranges in USD, not adjusted for Denison. Each row names its basis and the month we checked it.
| Job | Low | Typical | High | Basis | Checked |
|---|---|---|---|---|---|
| AC replacement | $3,887 | $5,978 | $8,073 | Per system, installed (unit plus labor); typical range of customer-reported jobs. US national range | October 2026 |
| Furnace replacement | $2,823 | $4,814 | $6,896 | Per system, installed; typical range of customer-reported jobs. US national range | October 2026 |
In Iowa, Iowa Plumbing and Mechanical Systems Board (Department of Inspections, Appeals and Licensing) licenses Mechanical (HVAC, refrigeration, hydronic) licenses.
No chip usually means we have not matched a state record yet. Check the lookup yourself before you hire.
Guide checked October 2026. How we verify licenses
In Iowa, 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 7 Denison HVAC contractors on ten 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. A business with no Google reviews scores zero on rating, review volume and recency. Other unknown factors are left out, 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 Denison data |
|---|---|---|---|
| Reputation | 25% | Google star rating, adjusted for how many reviews back it | Measured |
| Credentials | 15% | Active state license, bond and workers’ comp on file | Not yet collected |
| Review volume | 10% | Number of Google reviews, compared with the most-reviewed business on the list | Measured |
| Recency | 5% | Share of reviews from the last 12 months | Not yet collected |
| Availability | 5% | Weekly open hours, Saturday, Sunday, 24/7 or same-day | Measured |
| Trade focus | 10% | How clearly the business does this trade (its Google category and name) | Measured |
| Proximity | 5% | Based in the city scores highest, less the farther away it is | Measured |
| Claimed profile | 10% | The business has claimed its ContractorsRanked profile (free or paid earn the same) | Measured |
| Partnered | 5% | The business links to ContractorsRanked from its own website with our badge, checked periodically | Measured |
| ContractorsRanked reviews | 10% | Verified customer reviews collected by ContractorsRanked: their rating and how many there are | Measured |