Weil-McLain
Weil-McLain designs, manufactures, and markets hydronic heating equipment — including cast-iron and condensing boilers, heat pumps, indirect-fired water heaters, and controls — for residential, commercial, and institutional buildings across North America, sold through distributors and HVAC contractors.
- Company typePrivate
- Founded1881
- HeadquartersWillowbrook, United States
- Headcount501–1,000
- GTM typeB2B
- OfferingHardware or Manufacturing
What Weil-McLain does
Weil-McLain, operating legally as WM Technologies LLC, designs, manufactures, and markets hydronic heating equipment for residential, commercial, and institutional buildings across North America. Founded in Chicago in 1881 by Isadora and Benjamin Weil and headquartered in Burr Ridge, Illinois, the company runs two manufacturing facilities: a 100+ year cast-iron boiler plant in Michigan City, Indiana and a newer facility in Eden, North Carolina producing condensing and high-efficiency boilers. Its product portfolio spans residential and commercial gas, oil, and condensing boilers (including the ECO Tec, Evergreen Pro, SVF stainless firetube, SlimFit, and LGB series), the ECO Hybrid heat pump system, indirect-fired water heaters, hydronic baseboards, and a suite of boiler controls (BCP-3, BMC, BSC).
Underlying technology centers on cast-iron, stainless steel, and aluminum heat exchanger designs paired with advanced boiler control systems, including modulating and sequencing controls for multi-boiler installations and the ProTools contractor diagnostics app. The company sells exclusively through a two-tier channel of authorized distributors and HVAC contractors, supported by a contractor locator, the Advantage loyalty program, training resources, a BIM Revit Library for architects and engineers, and dedicated distributor and sales-rep portals. End customers are fragmented across single-family homes, multifamily, offices, schools, restaurants, hotels, religious and government buildings, with case-study examples such as St. Paul Catholic Church in Valparaiso, Indiana. Weil-McLain claims the position of largest brand of boilers in North America and largest U.S. manufacturer of cast-iron boilers.
The business model is hardware sales of long-life capital equipment with associated replacement parts and accessories, distributed via wholesalers and contractors at quote-based pricing. A 2025 product launch — the ECO Hybrid Heat Pump System — was recognized as the #1 Product of the Year by Plumbing & Mechanical magazine. Footer references to SPX Technologies and a careers page hosted at careers.spx.com suggest a corporate affiliation, though explicit ownership documentation is not provided in the source data. No public listing, venture funding, or institutional investor information is disclosed.
Weil-McLain firmographics
Firmographics- Name
- Weil-McLain
- Legal name
- WM Technologies LLC
- Website
- https://weil-mclain.com
- Company type
- Private
- Founded year
- 1881
- Operating status
- Operating
- Headcount range
- 501–1,000 employees
- Short description
- Weil-McLain designs, manufactures, and markets hydronic heating equipment — including cast-iron and condensing boilers, heat pumps, indirect-fired water heaters, and controls — for residential, commercial, and institutional buildings across North America, sold through distributors and HVAC contractors.
- Ownership category
- akta.pro rank
Weil-McLain industry classification
Industry- Product category
- Hydronic Heating Equipment
- NAICS
- Heating Equipment (except Warm Air Furnaces) Manufacturing (333414), Power Boiler and Heat Exchanger Manufacturing (33241)
- SIC
- Heating Equipment, Except Electric & Warm Air Furnaces (3433)
- akta.pro primary industry
- Boilers, Furnaces & Process Heating Equipment (IMAHAKAD)
- akta.pro secondary industries
- Heat Exchangers, Coils & Hydronic HVAC Components (IMADANAF), Heat Transfer Equipment (Heat Exchangers, Boilers, Condensers) (IMAHAEAC), Boiler & Hydronic Heating System Installation (HSAOAGAF)
Keywords
Where Weil-McLain is headquartered
LocationHeadquarters
- HQ city
- Willowbrook
- HQ country
- United States
- HQ region
- North America
Offices3 records
Markets served
Weil-McLain business model
Business model- GTM type
- B2B
- Offering type
- Hardware or Manufacturing
- Cost components
- Supply Chain, Operations, Personnel, Technology or R&D, Marketing or Sales, Infrastructure
Revenue model
- Boiler and Heating Equipment Sales: Weil-McLain generates revenue through the manufacture and sale of hydronic heating equipment including residential and commercial boilers, heat pumps, indirect-fired water heaters, controls, and baseboards. Products are sold through a network of distributors and contractors to end customers in residential, commercial, and institutional building sectors.
Go-to-market motion1 record
Distribution channels3 records
Marketing channels4 records
Weil-McLain product offering
Product offeringCore offering
Weil-McLain designs, manufactures, and markets hydronic heating equipment, including residential and commercial cast iron, stainless steel, and aluminum heat exchanger boilers (gas-fired, oil-fired, and condensing high-efficiency models), indirect-fired water heaters, the ECO Hybrid heat pump system, hydronic baseboards, and boiler control systems. Products are sold across North America through authorized distributors and HVAC contractors for use in single-family homes, apartments, commercial buildings, and institutional facilities. Supporting tools include the ProTools contractor app, Parts Selector, Product Comparison Tool, and a BIM Revit library.
Product overview
Weil-McLain is a leading North American manufacturer of hydronic heating systems, offering a comprehensive portfolio of residential and commercial boilers, heat pump systems, indirect-fired water heaters, controls, and baseboards. The product lineup includes high-efficiency condensing boilers (ECO Tec, AquaBalance, Evergreen Pro, GV90+, Ultra), conventional gas and oil boilers (CGa, CGi, EG Series, SGO, WGO, WTGO), commercial-grade boilers (SlimFit, SVF stainless vertical firetube series, 80/88/94 Series, LGB Series), the ECO Hybrid heat pump system for hybrid heating, and Aqua Pro/Aqua Plus indirect water heaters. Supporting these products are control systems (BCP-3, Boiler Control Panels, BMC, BSC), contractor tools (ProTools app, Parts Selector, Product Comparison Tool), and BIM resources. The company manufactures in Michigan City, Indiana and Eden, North Carolina, and has been in business since 1881.
Differentiator
Problem solved
Functional benefit
Products and services
- ECO Tec Gas Boiler
Quantifiable outcome
- ECO Tec offers up to 95% AFUE (Annual Fuel Utilization Efficiency)
- +1 more outcomes
Companies that use Weil-McLain
Customer profileNamed customers2 records
Segments3 records
Ideal customer profiles3 records
Weil-McLain technology and API
TechnologyTechnology focussed No
API detail
- Has API
- No
- API docs
- API detail
Core technology
AI maturity
App detail
Feature6 records
Weil-McLain partnerships and signals
Strategic signalScale indicators2 records
Recent moves6 records
Expansion highlights5 records
Weil-McLain competitors and assessment
Company assessmentDirect peers
- Navien: Manufacturer of condensing combi boilers (NPE, NCB) and stainless-steel heat-exchanger water heating products. Overlaps directly with Weil-McLain's AquaBalance and ECO Tec combi/high-efficiency residential offerings.
- U.S. Boiler Company: U.S. manufacturer of residential cast-iron and high-efficiency condensing boilers (K2, Aspen, ESC, Accel). Directly comparable to Weil-McLain in product category, channel model (distributor/contractor), and customer base in the U.S. hydronic market.
- Viessmann: German-based global manufacturer of hydronic heating (Vitodens, Vitoradial) with strong North American presence. Closely comparable in residential/commercial boiler portfolio, condensing technology, and controls integration.
- Lochinvar: Manufacturer of high-efficiency condensing boilers (FTXL, FBN, Knight) and commercial water heaters. Directly comparable to Weil-McLain's commercial condensing line (SlimFit, SVF) and competes in the same commercial-institutional segment.
- Burnham Holdings: Parent of Burnham, Crown Boiler, and Bryan Steam brands, manufacturing cast-iron and commercial steel boilers for residential and commercial hydronic markets. Comparable as a U.S. hydronic boiler manufacturer with overlapping channel and product portfolio.
Broad incumbents
- Bosch Thermotechnology: Division of Bosch that markets residential and commercial boilers (Greenstar, Buderus) along with broader HVAC and water heating products. Overlaps with Weil-McLain's residential gas-fired and commercial hydronic lines as a broader-portfolio incumbent.
- Carrier: Global HVAC incumbent (now part of Carrier Global) producing furnaces, boilers, heat pumps, and commercial HVAC systems. Comparable as a broad-portfolio incumbent with overlapping commercial heating offerings and increasing heat-pump focus.
- Lennox International: HVAC manufacturer offering residential and commercial furnaces, heat pumps, and boilers. Comparable to Weil-McLain in the commercial heating space and as a residential competitor pivoting toward high-efficiency heating.
- Trane Technologies: Global HVAC manufacturer offering commercial boilers (Runtrary), chillers, and heat pumps. Comparable in the commercial-institutional hydronic and broader thermal equipment market where Weil-McLain competes with SlimFit and SVF lines.
Regional players
- F.W. Webb Company: Large Northeast U.S. plumbing, heating, and HVAC wholesale distributor that competes in the channel layer adjacent to Weil-McLain's distributor network, supplying competing hydronic brands to contractors.
Market position
Strengths4 records
Weaknesses4 records
Competitive moat4 records
Key risks5 records
Key highlights6 records
Customer concentration
Weil-McLain social profiles
Digital presenceWeil-McLain financial estimates
Financial estimateRevenue estimate
Valuation estimate
Weil-McLain leadership team
Management profileNumber of profiles
Weil-McLain funding detail
Funding detailFunding overview
Funding rounds
Investors
Funding detail is available on the Subscription and Enterprise plan.Contact sales →
Weil-McLain M&A and investment
M&A and investmentM&A
Investments
M&A and investment is available on the Subscription and Enterprise plan.Contact sales →
Frequently asked questions about Weil-McLain
What does Weil-McLain do?
Weil-McLain designs, manufactures, and markets hydronic heating equipment, including residential and commercial cast iron, stainless steel, and aluminum heat exchanger boilers (gas-fired, oil-fired, and condensing high-efficiency models), indirect-fired water heaters, the ECO Hybrid heat pump system, hydronic baseboards, and boiler control systems. Products are sold across North America through authorized distributors and HVAC contractors for use in single-family homes, apartments, commercial buildings, and institutional facilities. Supporting tools include the ProTools contractor app, Parts Selector, Product Comparison Tool, and a BIM Revit library.
Is Weil-McLain a public or private company?
Weil-McLain is a private company. It is classified as corporate owned and is currently operating.
When was Weil-McLain founded?
Weil-McLain was founded in 1881. It employs 501 to 1,000 people.
Where is Weil-McLain based?
Weil-McLain is headquartered in Willowbrook, United States, in the North America region.
How does Weil-McLain make money?
One revenue line is on record: boiler and Heating Equipment Sales.
Who are Weil-McLain's main competitors?
Direct peers on record are Navien, U.S. Boiler Company, Viessmann, Lochinvar and Burnham Holdings. Broad incumbents are Bosch Thermotechnology, Carrier, Lennox International and Trane Technologies. F.W. Webb Company is listed as a regional player.
Does Weil-McLain have an API?
No public API is recorded for Weil-McLain.
What industry is Weil-McLain in?
Weil-McLain's product category is Hydronic Heating Equipment. Its primary akta.pro industry code is IMAHAKAD, Boilers, Furnaces & Process Heating Equipment, with a secondary code of IMADANAF, Heat Exchangers, Coils & Hydronic HVAC Components. Its NAICS code is 333414 and its SIC code is 3433.