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TRUSTED BY LONGMONT, CO HOMEOWNERS

  • Average homeowner rating star icon4.6
    Average homeowner rating
  • Verified reviews icon541
    Verified heating and air conditioning services reviews

Top-Rated Heating and air conditioning pros in Longmont - Updated Nov 2026

Avatar for M & H Air, LLC
M & H Air, LLC
5.0(
18
)
Central A/C - Service or RepairGas Furnace / Forced Air Heating System - InstallCentral A/C - Install+14 more

Serving Longmont, CO and surrounding areas

Approved

In business since 2001

Free estimates

Credit card accepted

"I had an excellent experience with this HVAC company. Their team was highly professional, knowledgeable, and focused from start to finish. They took the time to explain everything clearly, completed the work efficiently, and demonstrated great attention to detail. It’s refreshing to work with a company that values quality, expertise, and customer service. I highly recommend them to anyone looking for reliable HVAC professionals."
M & H Air, LLC
Victory Outreach Church
2 neighbors recently requested a quote
Avatar for Behold Heating & Cooling Services
Behold Heating & Cooling Services
4.9(
47
)
Central A/C - Service or RepairGas Furnace / Forced Air Heating System - RepairThermostat - Repair or Reprogram+2 more

Serving Longmont, CO and surrounding areas

Approved

In business since 2023

Free estimates

Emergency services offered

"I had a great experience from start to finish with this company. They were able to install my new AC unit quickly, which I was thankful for, considering how hot it has been. Throughout the entire process, they were transparent with their pricing, explained everything clearly, and never made me feel pressured. Dylan and Tristan were incredibly knowledgeable, professional, respectful, and kind. They took the time to answer all of my questions and made sure I understood what was being installed and why. I was honestly pretty stressed about having to replace my AC unit, but they made the entire experience easy and worry-free. I would absolutely recommend this company to anyone looking for honest, reliable HVAC service. Their customer service and quality of work exceeded my expectations, and I couldn't be happier with the experience."
Boiler Repair/Replacement
Boiler Replacement and Repipe
Boiler Replacement and Repipe
Furnace, AC, Water Heater Replacement
Furnace Tune-up

+35

Response time6 hrs
Response rate100%
83 neighbors recently requested a quote
Avatar for Mountain Pro HVAC Services, LLC
Mountain Pro HVAC Services, LLC
5.0(
126
)
Central A/C - Service or RepairElectric Furnace / Forced Air Heating System - RepairElectric Furnace / Forced Air Heating System - Repair - For Business+4 more

Serving Longmont, CO and surrounding areas

Approved

In business since 2018

Free estimates

Emergency services offered

"Our furnace wasn't working one evening and they came out after hours to help troubleshoot the problem. He gave us the option to pay a warehouse opening fee and have it fixed that night or do it first thing when they opened in the morning. He also identified some other issues with our furnace that was hurting efficiency that he fixed while he was there. Great service and will definitely call them again with any HVAC problems I have."
Maintenance Services
Maintenance Services
Maintenance Services
Maintenance Services
New AC / Furnace Install

+4

Response time11 hrs
Response rate92%
Recommended by100%of homeowners
Avatar for One Hour Heating & Air Conditioning - Loveland
One Hour Heating & Air Conditioning - Loveland
4.7(
208
)
Air Ducts & Vents - Clean

Serving Longmont, CO and surrounding areas

Approved (Corporate)

Super Service Award Winner

In business since 1978

Free estimates

Emergency services offered

"Brian, the HVAC technician was professional, friendly and extremely knowledgeable, he provided a full estimate before starting the work and then performed the repair immediately. We were back up and running in minutes. Well Done 1 hr team."
4 neighbors recently requested a quote
Recommended by92%of homeowners
Avatar for HighPoint HVAC
HighPoint HVAC
5.0(
23
)
Air Ducts & Vents - Clean

Serving Longmont, CO and surrounding areas

Approved

Credit card accepted

"Highly recommend Owen?s company! We scheduled to clean our Air Ducts and the results were incredible! I?ll definitely use them again. If you looking for good quality & honest work, you can?t do better than HighPoint HVAC"
2 neighbors recently requested a quote
A-Moonlight Heating & Air Conditioning
5.0(
52
)
Central A/C - Service or RepairGas Furnace / Forced Air Heating System - Repair

Serving Longmont, CO and surrounding areas

Approved

In business since 2014

Emergency services offered

Warranties offered

"Quickly worked out a long term problem from an incorrect furnace installation by another installer. Corrected the problem at a very fair price. They are now my preferred HVAC company."
Response time3 hrs
2 neighbors recently requested a quote
Recommended by96%of homeowners
Avatar for Your Comfort Heating and Cooling
Your Comfort Heating and Cooling
5.0(
19
)
Ductless Mini-split A/C - Install or ReplaceDucts & Vents - Install or ReplaceGas Boiler or Radiator Heating System - Repair+8 more

Serving Longmont, CO and surrounding areas

Approved

In business since 2008

Free estimates

Emergency services offered

"We had two AC units and a new furnace installed they were prompt, efficient, very respectful and great customer service! Dean was an absolute pleasure to work with, they have earned my business for life on any HvAC services I might need! Highly recommend"
New Amana Furnace
New Amana Heat Pump
High Efficiency
Outside Condensers
two new condensers

+3

Response time2 hrs
Response rate98%
18 neighbors recently requested a quote
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Heating and Air Conditioning FAQs, answered by experts

Water buildup in your HVAC system is a cause for alarm. If water accumulates in your ductwork, it can drastically lower your home's air quality and create safety hazards. These risks include mold growth, damage to your HVAC system, and attracting pests that are seeking water into your ducts. Proper insulation and sealing of ducts can prevent this, and regular inspection and maintenance can address water damage problems before they become too severe.

Running a window air conditioner unit costs about $0.06 to $0.88 per hour. Choosing the correct size air conditioner can help it run more efficiently.

If the air coming from your AC unit is cool but never quite cold, there are a few reasons this might be happening. For starters, it could signal that your refrigerant levels are low. If there are no other indications of this particular issue, like hissing noises or frozen refrigerant lines, anything from dirty filters to damaged condenser or evaporator coils could be responsible for the problem.

If your whole house is cold that’s one thing, but what if you only have a few rooms that are cold? First, you need to determine why this may be happening. A good place to start is to investigate the potential causes listed in this article—heat transfer, airflow, thermostat problems, humidity, and insulation. Once you’ve narrowed down the issue, you’d apply the same principles to the cold rooms as you would to the entire home.

Yes, scorpions can enter a home through AC vents, especially if the system is not well-sealed. As excellent climbers, they can scale a home's exterior and squeeze through gaps as small as 1/16 of an inch. Scorpions are often attracted to the moisture around air conditioning ducts or seek cooler areas during hot weather, using vents as a pathway inside. They may slip through small openings where the duct meets the vent cover and travel within walls before emerging. To prevent this, inspect your vents, seal any gaps, and consider installing fine mesh screens.

The Longmont, CO homeowners’ guide to heating and air conditioning services

From average costs to expert advice, get all the answers you need to get your job done.