What do Boilermakers Do


Boilermakers and boilermaker mechanics make, install, and repair boilers, closed vats, and other large vessels or containers that hold liquids and gases. Boilers heat water or other fluids under extreme pressure for use in generating electric power and to provide heat and power in buildings, factories, and ships. Tanks and vats are used to store and process chemicals, oil, beer, and hundreds of other products.

In addition to installing and maintaining boilers and other vessels, boilermakers also help erect and repair air pollution equipment, blast furnaces, water treatment plants, storage and process tanks, and smoke stacks. Boilermakers also install refractory brick and other heat-resistant materials in fireboxes or pressure vessels. Some install and maintain the huge pipes used in dams to send water to and from hydroelectric power generation turbines.

Boilers and other high-pressure vessels used to hold liquids and gases usually are made in sections by casting each piece out of steel, iron, copper, or stainless steel. Manufacturers increasingly are automating this process to improve the quality of these vessels. Boilermakers weld sections of the boiler together, often using robotic welding systems or automated welding machines. Small boilers may be assembled in the manufacturing plant; larger boilers usually are prefabricated in numerous pieces and assembled on site, although they may be temporarily assembled in a fabrication shop to ensure a proper fit before final assembly at the permanent site.

Because boilers last a long time—sometimes 50 years or more—boilermakers need to regularly maintain them and upgrade components, such as boiler tubes, heating elements, and ductwork, to increase efficiency. They frequently inspect fittings, feed pumps, safety and check valves, water and pressure gauges, boiler controls, and auxiliary machinery. For closed vats and other large vessels, boilermakers clean or supervise cleaning of the vats using scrapers, wire brushes, and cleaning solvents. They repair or replace defective parts using hand and power tools, gas torches, and welding equipment, and may operate metalworking machinery to repair or make parts. They also dismantle leaky boilers, patch weak spots with metal stock, replace defective sections, and strengthen joints.

Before making or repairing a fabricated metal product, a boilermaker studies design drawings and creates full size patterns or templates, using straightedges, squares, transits, and tape measures. After the various sized shapes and pieces are marked out on metal, boilermakers use hand and power tools or flame cutting torches to make the cuts. The sections of metal are then bent into shape and accurately lined up before they are welded together. If the plate sections are very large, heavy cranes are used to lift the parts into place. Boilermakers align sections using plumb bobs, levels, wedges, and turnbuckles. They use metalworking machinery and other tools to remove irregular edges so that metal pieces fit together properly. They then join them by bolting, welding, or riveting. Boilermakers also align and attach water tubes, stacks and liners, safety and check valves, water and pressure gauges, and other parts, and test complete vessels for leaks or other defects.

Work Environment

Boilermakers held about 14,900 jobs in 2020. The largest employers of boilermakers were as follows:

  • Utility system construction - 23%
  • Nonresidential building construction - 13%
  • Plumbing, heating, and air-conditioning contractors - 10%
  • Fabricated metal product manufacturing - 6%
  • Other building equipment contractors - 3%

Boilermakers do physically demanding work in cramped spaces inside boilers, vats, or tanks that are often dark, damp, noisy, and poorly ventilated. They frequently work outdoors in all types of weather, including extreme heat and cold.

Because dams, boilers, storage tanks, and pressure vessels are large, boilermakers frequently work at great heights. For example, they may be hundreds of feet above the ground when working on a dam.                                                                                                               

Injuries and Illnesses

The work that boilermakers do can be dangerous. Workers must follow specific safety procedures to avoid injuries and illnesses and must be mindful of potential dangers to themselves and their coworkers. To reduce the risk of injury, boilermakers wear hardhats, earplugs, safety glasses, and other protective equipment. When working in enclosed spaces, boilermakers often wear a respirator.

Work Schedules

Most boilermakers work full time, and work schedules may vary. Boilermakers may experience extended periods of overtime when equipment is shut down for maintenance or repair, or when necessary to meet construction or production deadlines. In contrast, because most field construction and repair is contract work, there may be periods of unemployment upon completion of a contract.

Boilermakers may travel to worksites and be away from home for extended periods.

Education & Training Required

Boilermakers learn their trade through formal apprenticeships offered through unions or employers or from a combination of trade and technical school training and employer-provided training. Training usually includes both boilermaking and structural fabrication. Apprenticeship programs usually consist of 6,000 hours or 4 years of paid on-the-job training, supplemented by a minimum of 144 hours of classroom instruction each year in subjects such as set-up and assembly rigging, plate and pressure welding, blueprint reading, and layout. Those who finish registered apprenticeships are certified as fully qualified journey-level workers.

Most apprentices must be at least 18 years old, a high school graduate or holder of a GED, and be legally authorized to work in the United States. Those with welding training or a welding certification will have an advantage in applying for apprenticeship programs. When an apprenticeship becomes available, the local union usually publicizes the opportunity by notifying local vocational schools and high school vocational programs. Education often continues throughout a boilermaker’s career as they often attend classes or seminars to learn about new equipment, procedures, and technology.

Other Skills Required

The work of boilermakers requires a high degree of technical skill, knowledge, and dedication. Because the tools and equipment used by boilermakers are typically heavier and more cumbersome than those in other construction trades, having physical strength and stamina is important. Good manual dexterity is also important.

How to Advance

Some boilermakers advance to supervisory positions. Because of their extensive training, those qualified through apprenticeships usually have an advantage in getting promoted over those who have not gone through the complete program.

Job Outlook

Employment of boilermakers is projected to show little or no change from 2020 to 2030.

Despite limited employment growth, about 1,300 openings for boilermakers are projected each year, on average, over the decade. Most of those openings are expected to result from the need to replace workers who transfer to different occupations or exit the labor force, such as to retire.


Boilers typically last for decades, but there will be an ongoing need for boilermakers to replace and maintain parts, such as boiler tubes, heating elements, and ductwork. Boilermakers will also continue to be needed to install new equipment, including boilers, pressure vessels, air pollution abatement equipment, and storage and process tanks.

However, the shift away from coal-fired electricity generation will reduce the need for boilermakers. Renewable photovoltaic and wind generation systems do not have boilers, and natural gas plants require less ongoing boiler maintenance than coal plants.


The median annual wage for boilermakers was $64,290 in May 2021. The median wage is the wage at which half the workers in an occupation earned more than that amount and half earned less. The lowest 10 percent earned less than $46,040, and the highest 10 percent earned more than $100,240.

In May 2021, the median annual wages for boilermakers in the top industries in which they worked were as follows:

  • Nonresidential building construction - $77,240
  • Plumbing, heating, and air-conditioning contractors - $72,160
  • Other building equipment contractors - $68,940
  • Utility system construction - $64,320
  • Fabricated metal product manufacturing - $53,610

Apprentices receive less pay than fully trained boilermakers. They receive pay increases as they learn more skills.

Most boilermakers work full time, and work schedules may vary. Boilermakers may experience extended periods of overtime when equipment is shut down for maintenance or repair, or when necessary to meet construction or production deadlines. In contrast, because most field construction and repair work is contract work, there may be periods of unemployment upon completion of a contract.

Boilermakers may travel to worksites and be away from home for extended periods.

Academic Programs of Interest

A Construction Boilermaker program will teach a student how to use blueprints and other plans to construct, install, and repair boilers, tanks, and other large containers that hold liquids and gases. Boilers are used to contain everything from steam in an electric power plant to oil, chemicals and other liquids that we use daily. A Construction Boilermaker program will also teach a student how to... more