
Find the Best Furnace Installation & Replacement Contractors for Your Business
No obligation • Fast responses • Nationwide coverage

Why you can trust HVAC Firms
HVAC Firms is a leading United States resource for evaluating HVAC service providers. Our team researches companies, checks credentials, and reviews customer feedback to present clear, unbiased information. Listings and rankings are based on merit, and companies cannot pay to change our editorial content.
Search providers near you
Top Furnace Installation & Replacement Contractors in Longmont, Colorado Ranked
A reliable and efficient furnace is essential for comfort and safety during Longmont's cold winters. Whether you're upgrading an aging system or installing a new one, understanding your options for home heating is key. This guide provides a detailed look at the furnace installation and replacement process, the specific considerations for our Colorado climate, and how to find qualified local professionals to ensure your project is completed to the highest standards.
Understanding Your Furnace Options in Longmont
Choosing the right heating system for your home involves more than just picking a unit off the shelf. The unique climate and regulatory environment in Colorado make certain types of furnaces and heat pumps particularly well-suited for Longmont residences.
Natural Gas Furnaces are the most common choice for home heating in the area. They are preferred for their ability to produce powerful, consistent heat efficiently during our cold winters. Modern high-efficiency, variable-speed models are especially popular as they offer significant savings on long-term operating costs while providing superior comfort 1.
Electric Furnaces are typically used in homes without access to natural gas lines. While they often have a lower initial purchase price, they generally come with higher operational costs due to electricity rates 2.
Heat Pumps are gaining substantial popularity. Modern cold-climate heat pumps can efficiently heat homes even in freezing temperatures and can be configured in a dual-fuel system paired with a gas furnace for the coldest days, or act as a primary heat source 3. This technology offers an efficient alternative or complement to traditional furnace setups.
Boilers, which provide radiant heat through water, are sometimes found in older homes but are less common for new installations 4. The decision between these systems depends on your home's existing infrastructure, fuel availability, and your efficiency goals.
Why Climate and Regulations Matter for Your Installation
Longmont's high altitude and dry, cold winters directly impact furnace selection and performance requirements. Simply installing a standard unit isn't enough; your system must be engineered for local conditions.
Combating Cold Winters & Altitude: High-efficiency furnaces with an Annual Fuel Utilization Efficiency (AFUE) rating of 90% or higher are strongly recommended. These units extract more heat from the same amount of fuel, which is crucial for managing energy bills during extended freezing periods 5. Proper sizing and installation are also critical at our altitude, as air density affects combustion and heat transfer.
New Colorado Emissions Regulations (HB23-1161): This is a critical factor for any new installation. Starting January 1, 2026, all new natural gas furnaces installed in Colorado must meet stricter Ultra-Low NOx (ULN) standards, emitting less than or equal to 14 nanograms per joule of nitrogen oxide 6 7. This environmental regulation is designed to improve air quality. For homeowners, it means that compliant furnaces may have a higher equipment cost, and planning an installation before this deadline may offer different options and pricing.
Managing Dry Air: Our arid climate means indoor air can become extremely dry when heated. It is very common for professionals to recommend installing a whole-home humidifier alongside a new furnace system to maintain comfortable humidity levels and protect wood furnishings and your health.
The Professional Installation Process: What to Expect
A proper furnace installation is a multi-step process conducted by licensed technicians. It's far more complex than simply swapping an old box for a new one and ensures safety, efficiency, and compliance with all codes.
- Site Assessment & Load Calculation: A crucial first step where a technician evaluates your home's insulation, window quality, square footage, and layout. This determines the correct British Thermal Unit (BTU) size; a unit that is too large or too small will be inefficient and uncomfortable.
- Removal of Old Unit: The existing furnace is safely disconnected from gas, electrical, and venting systems, removed from your home, and responsibly disposed of.
- System Modifications & Prep: To meet modern safety and efficiency codes, technicians may need to update venting (often to PVC), gas lines, electrical wiring, or the condensate drain system.
- Installation & Connection: The new high-efficiency furnace is carefully positioned, leveled, and connected to the gas line, electrical supply, and existing ductwork. All connections are sealed to prevent leaks 8.
- Testing & Calibration: The system is started and tested for proper ignition, airflow, temperature rise, and safe carbon monoxide levels. The technician will calibrate the system for optimal performance 9 10.
- Inspection & Certification: A final inspection ensures the installation meets Colorado's strict safety and environmental standards. You should receive all necessary documentation and warranties for your new equipment 11.
Find the perfect furnace installation & replacement contractors for your needs
Get personalized recommendations and expert advice
Cost Guide for Furnace Installation in Longmont
Investing in a new heating system is a significant decision, and understanding the costs involved helps in planning and budgeting. Prices in Northern Colorado for 2025-2026 vary based on system efficiency, capacity, and the complexity of the installation 12 13.
| Furnace Type/Size | Estimated Total Cost (Installed) |
|---|---|
| Standard Efficiency Furnace (40K-60K BTU) | $4,500 - $6,500 |
| Energy Star / High-Efficiency Furnace (90%+ AFUE) | $5,500 - $7,500 |
| Ultra-Low NOx Compliant Furnace (Required 2026+) | $8,500 - $12,000+ |
| Average System for a 1500 sq ft Home | $4,800 - $6,200 |
Table based on aggregated local industry estimates for professional installation including the unit 14 15.
Several key factors influence the final price:
- System Efficiency: High-efficiency (90%+ AFUE) and Ultra-Low NOx models have a higher upfront cost but provide long-term savings on energy bills and ensure regulatory compliance 16 17 18.
- Installation Complexity: Costs increase if modifications to ductwork, gas lines, or electrical systems are required. The physical accessibility of the installation site (e.g., attic or crawlspace) also plays a role 19.
- Additional Components: Adding accessories like a high-efficiency air filter, smart thermostat, or whole-home humidifier will add to the total project cost but can enhance comfort and system performance 20.
Choosing a Qualified Local Professional
The quality of the installation is as important as the quality of the furnace itself. A poor installation can undermine the efficiency, safety, and lifespan of even the best equipment. When evaluating local providers for your heating system project, ensure they are licensed, insured, and have specific experience with installations in the Longmont and Boulder County area. Look for companies that perform a detailed load calculation, explain the options relevant to Colorado's climate and upcoming regulations, and provide clear, written estimates. Checking reviews and asking for references on recent installations can give you confidence in your choice.
Frequently asked questions
Sources
Footnotes
-
Heat Pump vs. Furnace: Which Heating System is Best? | CO - https://bryantcolorado.com/heat-pump-vs-furnace-which-heating-system-is-best-for-colorado-homes/ ↩
-
Longmont HVAC & Electrical Services | Installation & Repair - https://kapplermechanical.com/city/longmont-co/ ↩
-
Heating Colorado Homes - https://extension.colostate.edu/resource/heating-colorado-homes/ ↩
-
Furnace vs Boiler vs Heat Pump for Heating Colorado Homes - https://patriotpros.com/furnace-vs-boiler-vs-heat-pump/ ↩
-
Different Types of Furnaces for Your Home Heating Needs - https://totalcomfortcooling.com/different-types-of-furnaces-for-your-home-heating-needs/ ↩
-
What Colorado Homeowners Need to Know Now That ULN ... - https://imsheatingandair.com/your-furnace-your-money-your-decision-what-colorado-homeowners-need-to-know-now-that-uln-regulations-are-in-effect/ ↩
-
Colorado Furnace Rules 2026: What Homeowners Need to Know - https://vangenderenheating.com/colorados-new-furnace-rules-what-homeowners-need-to-know-before-2026/ ↩
-
Step-by-Step HVAC Installation Guide - Carrier - https://www.carrier.com/residential/en/us/products/air-conditioners/hvac-installation/ ↩
-
New Furnace Installation: What to Expect - Navien - https://www.navieninc.com/blog/notice/new-furnace-installation-what-to-expect ↩
-
How to Install Furnace: Step-by-Step Homeowner Guide - https://callwhitney.com/how-to-install-furnace-step-by-step-guide/ ↩
-
Professional Furnace Installation Services in Longmont - https://stoneheatingandair.com/furnace-installation-services-in-longmont/ ↩
-
Property Managers: Colorado's Furnace Regulations Are Now In ... - https://imsheatingandair.com/property-managers-colorados-furnace-regulations-are-now-in-effect-pre-regulation-inventory-is-still-available/ ↩
-
How Much Does a New HVAC System Cost in Northern Colorado? - https://originphce.com/new-hvac-system-cost-northern-colorado/ ↩
-
Repair And Installation | Longmont, CO - Carbon Valley Heating & Air - https://carbonvalleyheatingandair.com/repair-installation/ ↩
-
How Much does a Air Conditioner Furnace combo cost - https://www.leonardsplaine.com/how-much-does-a-air-conditioner-furnace-combo-cost/ ↩
-
Professional Furnace Installation Services in Longmont - https://stoneheatingandair.com/furnace-installation-services-in-longmont/ ↩
-
Furnace Installation Costs: What to Expect and How to Budget ... - https://www.303heatingandair.com/furnace-installation-costs-what-to-expect-and-how-to-budget-for-it ↩
-
Article - https://coloradonaturalgas.com/Article/560/ ↩
-
HVAC Buying Guide 2025: Types, Installation Costs, FAQs - https://modernize.com/hvac ↩
-
How Much Does a Furnace Cost and Other FAQs About Furnaces - https://bendheating.com/how-much-does-a-furnace-cost-and-other-faqs/ ↩




