Meta Description: Compare 10 Duluth HVAC contractors for furnaces, boilers, heat pumps and AC. Each firm was checked on its site for services, Twin Ports base and credentials.
Heating is not optional in Duluth, Minnesota. Winters off Lake Superior are long, cold snaps can push a furnace or boiler to its limit for weeks, and many older homes on the hillside still run on hot water or steam heat. Picking the right Duluth HVAC contractor matters more here than in most of the country, whether you need a boiler replaced, a furnace repaired on a January night, or a cold-climate heat pump added for shoulder seasons and summer cooling.
This Top HVAC Companies In Duluth, MN For 2026 list covers ten HVAC companies in Duluth MN and the immediate Twin Ports area, including Hermantown and Superior, Wisconsin. Every firm was checked on its own website, or on a chamber or trade listing where the site could not be opened, for the services it offers, where it is based, and the licenses, bonds and certifications it claims. We only included facts we could find, and we describe claims as what each company says about itself.
The list runs from the most established, clearly local firms to smaller specialists. Start with the table for a quick comparison, then read the profiles to see which contractor fits your home or building and the kind of heating and cooling in Duluth you need.
HVAC Companies In Duluth, MN At A Glance
Company
Based In
Best For
Known For
MMT Heating & Cooling
Duluth (Miller Trunk Hwy)
Homeowners wanting 24-hour service and many fuel options
Bryant dealer, Mitsubishi Diamond Contractor, outdoor wood boilers, since 1993
A.G. O’Brien Plumbing & Heating Co.
Hermantown
Homes and commercial buildings needing plumbing and HVAC from one firm
Serving the Northland since 1934, third-generation family ownership
Krause Heating & Cooling
Duluth (West End)
Furnace and AC owners who value union-trained technicians
Family-run since 1982, NATE-certified technicians, custom ductwork
Northland Comfort Heating & Cooling
Duluth (Miller Trunk Hwy)
Boiler and cold-climate heat pump projects
Trane Comfort Specialist, Mitsubishi Diamond Contractor, listed MN mechanical bond
All Service Professionals (ASP)
Hermantown and Duluth
Households wanting HVAC, plumbing, electrical and septic in one call
MMT Heating & Cooling installs, repairs and maintains furnaces, boilers and air conditioners across the Duluth metro. The company lists its shop at 5501 Miller Trunk Highway, and it says it has served the area since 1993.
What sets MMT apart is the range of heating fuels it handles. Beyond gas furnaces and boilers, it sells heat pumps, ductless mini splits and dual fuel “hybrid heat” systems that pair a heat pump with a furnace, which suits Duluth homes that want efficient heating in spring and fall with gas backup in deep cold. It is also an authorized Central Boiler dealer for outdoor wood furnaces and sells wood pellet products, an unusual offer for a metro contractor. The firm says it is a factory authorized Bryant dealer and a Mitsubishi Electric Diamond Contractor, and it advertises 24-hour service. Indoor air quality products such as humidifiers, air purifiers, ventilators and UV lights round out the lineup.
MMT suits homeowners who want one contractor for a full furnace and AC replacement, those weighing a heat pump or dual fuel system, and rural or edge-of-town properties considering an outdoor wood boiler.
A.G. O’Brien Plumbing & Heating Co. handles plumbing, heating, cooling and HVAC installation, replacement, repair and maintenance for residential and commercial clients. The company says it has served the Northland since 1934, and the Duluth News Tribune reported that it operates from Hermantown’s industrial park, where it moved in 1999.
Longevity is the clear differentiator. According to the News Tribune, Irish immigrant Adam George O’Brien founded the business, and it is now run by the third generation of the Adatte family. The same report put the staff at about 92 people and named commercial projects including the Black Bear Event Center and the Hermantown Ice Arena. The company’s site lists sheet metal fabrication alongside its heating and cooling work and names a service area of seven counties: St. Louis, Douglas, Carlton, Pine, Itasca, Cook and Bayfield. That reach covers both the Minnesota and Wisconsin sides of the Twin Ports and much of the North Shore.
A.G. O’Brien fits property owners who want a long-established, larger crew that can take on plumbing and HVAC together, as well as businesses and apartment owners with commercial heating systems that need a contractor with the staff to match.
Krause Heating & Cooling installs and services furnaces, air conditioners, heat pumps and mini-splits, and it builds custom ductwork. The company is based at 2020 West 1st Street in Duluth’s West End and describes itself as family-run since 1982.
Krause leans on its trade background. It says its technicians are union-trained and NATE-certified, and it describes itself as one of the last union sheet metal contractor teams in the area. That sheet metal capability matters in Duluth, where older houses often need ductwork modified or rebuilt when a boiler-heated home adds central air or when a furnace is replaced with a different size unit. Carrier’s dealer directory lists Krause as a NATE dealer. The company is upfront about its service model: weekday hours run 8:00 AM to 4:30 PM, and weekend emergency service is offered for Carrier and Payne equipment only, so owners of other brands should plan accordingly.
Krause is a good match for homeowners who want a small family firm, those with Carrier or Payne equipment who value weekend coverage, and anyone whose project involves new or reworked ductwork rather than a simple swap.
Northland Comfort Heating & Cooling installs, maintains and repairs boilers, furnaces, air conditioning and cold-climate heat pumps for homes and commercial properties. It lists its address as 5722 Miller Trunk Highway in Duluth and names Duluth, Cloquet and Wrenshall among its service areas.
Northland Comfort publishes more credential detail than most local shops. Its site lists a Minnesota mechanical bond number, lead-safe renovation contractor status, CFC refrigerant handling certification, testing, adjusting and air balancing, and training in several gas and radiant piping systems. It says it is a Trane Dealer and Comfort Specialist and a Mitsubishi Diamond Contractor, and it works with Lochinvar and Weil-McLain boilers. The team page names its coordinator and installers, with the lead installer credited with more than 20 years of furnace and boiler installations. Beyond equipment, the company lists ductwork, sheet metal, new construction and remodeling work.
Northland Comfort suits homeowners replacing a boiler or adding a cold-climate heat pump, builders and remodelers who need HVAC on a new or renovated home, and anyone who wants to see a contractor’s bond and certifications listed before calling.
All Service Professionals, known locally as ASP, offers heating, air conditioning, plumbing, electrical, septic pumping, fireplace and duct cleaning services. It is headquartered at 5028 Miller Trunk Highway in Hermantown, lists a Duluth location on Venture Avenue, and also names offices in Cloquet and Two Harbors.
ASP’s strength is breadth and availability. Its heating and cooling pages cover furnace repair and replacement, boiler repair and replacement, AC repair and ductless split systems, and it lists 24/7 emergency service, which matters when a furnace quits during a Duluth cold snap. According to the Hermantown Chamber, the company traces back to Summit Mechanical Service, founded in 2000, and took its current name after a 2019 merger. The chamber listing also notes a specialty in radiant in-floor heating. ASP describes its plumbers, electricians and HVAC technicians as licensed and publishes a Minnesota license number on its Duluth page. Its service area extends into Superior and South Range on the Wisconsin side.
ASP fits households that would rather call one company for a furnace, a water heater and an electrical panel, and homeowners who want a firm with emergency heating coverage and several offices around the Twin Ports.
6.Design Heating — Hydronic, Radiant And Geothermal System Specialist
Design Heating focuses on high-efficiency boilers, oil-to-gas conversions, in-floor radiant heat, panel radiators and geothermal systems, and it also installs furnaces with air conditioning and ductless mini-splits. The company is based at 5131 Washburn Road in Duluth and says it was founded in 2016.
Design Heating stands out for its design credentials. It lists Certified Geothermal Designer status, IGSHPA accreditation as a trainer and installer, and training in ACCA Manual J, S and D, the industry methods for calculating heat loss, selecting equipment and sizing ductwork. It publishes its Minnesota license number and describes itself as licensed and bonded, and it lists BBB accreditation. For Duluth homes with hydronic heat and no ductwork, the company suggests ductless mini-split heat pumps for cooling and supplemental heat. The firm is clear about its limits: its FAQ says it does not offer emergency or 24/7 service, and it works weekdays from 7:00 AM to 5:30 PM, prioritizing same-week appointments.
Design Heating suits homeowners planning a boiler replacement, a radiant floor project or a geothermal system, where careful load calculations and system design matter more than round-the-clock repair calls.
Twin Ports Custom Climate provides residential heating and air conditioning, commercial and industrial HVAC, commercial refrigeration and indoor air quality products such as UV lights, HEPA filters and air exchangers. The company lists Superior, Wisconsin and Duluth, Minnesota as its service areas, and trade listings place it on Oakes Avenue in Superior. It says it was established in 2006.
The company advertises 24/7 emergency service and says it aims to respond to emergencies within two hours. It works with Trane, Mitsubishi, Weil-McLain and Lochinvar equipment, which covers furnaces, ductless systems and boilers. Its about page lists a Wisconsin HVAC Qualifier license, and its site displays the logo of the Minnesota Air Source Heat Pump Collaborative, a group focused on air source heat pumps in Minnesota. The commercial refrigeration side of the business is less common among Twin Ports HVAC shops and makes the firm a practical choice for restaurants, stores and other businesses with walk-in coolers or refrigerated cases as well as heating equipment.
Twin Ports Custom Climate is a sensible pick for Superior homeowners, Duluth businesses that need both HVAC and refrigeration service, and anyone who wants a contractor working both sides of the bridge.
Stone Plumbing & Heating handles heating, plumbing, and sewer and drain cleaning for residential and commercial customers. The company lists its office on Jean Duluth Road in Duluth and names a service area that runs from Duluth, Esko and Proctor up the North Shore to Two Harbors and Silver Bay.
On the heating side, Stone works with furnaces, boilers, radiant in-floor heating and heat pumps, and it names Weil-McLain, Navien and Lochinvar as brands its team knows. Those are common boiler and combination unit brands in older Duluth homes, so the firm is well placed for hydronic repairs and replacements. Stone advertises 24/7 emergency service for heating system failures as well as leaks and clogs, and it says it has more than 20 years of experience. The company handles work ranging from small repairs to large new construction projects. Its heating pages do not mention air conditioning, so homeowners looking mainly for central air should confirm what Stone offers before booking.
Stone suits homeowners in eastern Duluth and along the North Shore who rely on boilers or radiant heat, and households that want one company for heating emergencies and plumbing problems.
Kalkbrenner Plumbing & Heating offers boiler installation, maintenance and repair, garage unit heater repair and a full range of plumbing services. The company is based at 12802 West 9th Street in western Duluth and lists Carlton, Cloquet, Duluth, Esko, Hermantown, Proctor and Wrenshall as its service areas.
Kalkbrenner is a family-owned and operated business that says it has served the Duluth area for more than 30 years. Its heating work is concentrated on hydronic systems and unit heaters rather than forced air and air conditioning, which makes it a focused option for the many Duluth homes and garages heated by boilers. The company describes its technicians as licensed and insured and says it takes plumbing and heating emergency calls at any hour, including boiler and garage unit heater failures. On the plumbing side it lists backflow testing, leak detection, sump pumps, water heaters including tankless models, and bathroom renovation, so a single visit can cover both a boiler and the water heater next to it.
Kalkbrenner suits homeowners in western Duluth and Carlton County with boiler heat, and owners of heated garages and shops who need unit heater service from a small local firm.
10.A.W. Kuettel & Sons — Industrial Mechanical And HVAC Contractor Founded In 1924
A.W. Kuettel & Sons is a mechanical contractor and industrial metal fabricator offering mechanical, roofing and HVAC services. According to the Hermantown Chamber, the company is based at 3930 Airpark Boulevard in Duluth, near the airport.
The company’s history is one of the longest in the Duluth trades. The chamber listing says A.W. Kuettel started the business in Duluth in 1924 as a sheet metal and roofing company, and it now serves major regional industries across the Upper Midwest. That combination of HVAC, piping, sheet metal fabrication and roofing under one roof is aimed at large buildings and industrial sites, where ductwork, rooftop units and the roof itself often have to be coordinated on the same project. Kuettel is not a residential furnace repair shop, and homeowners will generally be better served by the firms higher on this list. For plants, institutions and commercial property owners in the Duluth area, though, it is one of the few locally rooted contractors with the fabrication capacity for this scale of work.
A.W. Kuettel & Sons suits industrial facilities, institutions and commercial property owners that need mechanical, HVAC and roofing work from a single Duluth contractor with in-house fabrication.
How To Choose An HVAC Company In Duluth, MN
Does The Contractor Install Cold-Climate Heat Pumps, And Do They Size Them For Duluth Winters?
Heat pumps are increasingly common in Duluth, but not every model performs well at subzero temperatures. Ask whether the contractor installs cold-climate rated equipment, how much heat the unit is rated to deliver at the low temperatures your home actually sees, and what backup heat will carry the house through the coldest stretches off Lake Superior. A good contractor will run a room-by-room load calculation, such as ACCA Manual J, rather than sizing by square footage, and will explain whether a ductless system, a ducted heat pump or a dual fuel setup paired with your existing furnace makes more sense.
What Happens If My Heat Goes Out On A January Night?
Emergency coverage varies widely, even among the firms on this list. Some advertise 24/7 service, some limit after-hours calls to customers or to certain equipment brands, and some do not offer emergency service at all. Ask before you need it: who answers the phone after hours, whether there is an extra charge, how quickly a technician typically arrives in winter, and whether maintenance plan customers get priority. With frozen pipes a real risk in a Duluth cold snap, it is worth knowing your contractor’s answer ahead of time.
Is The Company Licensed And Bonded For HVAC Work In Minnesota?
Ask any contractor for its Minnesota license or bond number and confirm it with the Minnesota Department of Labor and Industry before work begins. Some Duluth firms publish this on their websites; Northland Comfort and Design Heating both list a Minnesota mechanical bond number, for example. Also ask about insurance, whether the job needs a permit and inspection from the city of Duluth or your township, and who pulls it. On the Wisconsin side of the Twin Ports, credentials are issued by Wisconsin instead, so check that a Superior-based firm holds the right ones for your address.
Can They Work On Boilers, Radiators And Older Duluth Heating Systems?
Many Duluth houses, especially older homes on the hillside, are heated by hot water or steam boilers rather than forced air. If yours is, choose a contractor that regularly services hydronic systems and can talk through options such as high-efficiency condensing boilers, oil-to-gas conversions or adding radiant floor zones. If you also want air conditioning in a home without ductwork, ask whether they install ductless mini-splits so you do not have to tear into plaster walls for new ducts.
What Should A Written Quote Include?
A solid quote names the exact equipment brand and model, its efficiency rating, the labor and parts warranty terms, any ductwork, venting or electrical changes, permit costs and the expected installation timeline. Get at least two or three quotes for a full system replacement, and ask each Duluth HVAC contractor to explain any big differences in equipment size or scope rather than comparing price alone.
Conclusion
The right HVAC partner in Duluth, MN depends on what heats your building and how much risk you are willing to take in midwinter. For full-service furnace, AC and heat pump work with emergency coverage, MMT, A.G. O’Brien, Northland Comfort and ASP are strong starting points. Krause brings union sheet metal and ductwork skills, Design Heating, Stone and Kalkbrenner are good fits for boiler and radiant systems, Twin Ports Custom Climate covers Superior and commercial refrigeration, and A.W. Kuettel handles industrial projects.
Whichever firm you call, confirm its license or bond, its after-hours policy and its cold-climate experience before signing. For more local service providers, visit our Duluth, MN hub, and if your project also involves water heaters or pipes, see our list of the top plumbers in Duluth, MN.
