We are a full service Mechanical Contractor offering the support of a full-time professional team

Our in-house qualifications and team members include industry professionals such as:

Professional Engineers

Energy Managers

Indoor Air Quality Professionals

Master Plumbers

Master Electricians

Master Sheet Metal Technicians

Limited Electricians

CFC Universal Technicians

Unlimited Propane / Natural Gas Technicians

Unlimited Oil & Solid Fuel Technicians

Boiler and STM Engineers

Factory Trained Technicians

Lighting Specialists

Controls Engineers, Programmers, and Technicians

Scope Of Services

We provide turnkey design, installation & maintenance solutions for commercial, industrial & institutional HVAC, refrigeration & plumbing systems as well as newer sustainable technologies such as biomass, thermal, solar, and geothermal.  


Equipment Installation & Replacement

Thayer Corporation offers brand-agnostic expertise and the capacity to design, install, service and protect your mechanical assets, reduce capital expenditures, and realize energy savings. We provide solutions to keep your facility running efficiently, effectively and safely.

Engineered Design & Build

If you value time and results, Design/Build delivers on both counts.  Different from plan and spec, the Thayer team is involved from the earliest stages of a project, this allows us to ensure that all factors and variables are considered in the design; that the components are of the highest quality’;  that the installation is performed correctly and on time; and that your system will perform as promised. Single Sourced Design/Build is the most efficient method of delivering quality and efficiency in a construction project. It is about getting it done right the first time with a solution designed to your specific application

Heating Systems
  • Natural Gas, Oil, LP, Biomass
  • Furnaces
  • Steam Boilers
  • Hot Water Boilers
  • Hydronic Systems
  • Combustion Air
  • Air Handling Units
Air Conditioning Systems
  • DX Systems
  • Humidification Systems
  • Outside Air Systems
  • Chiller Systems
  • Cooling Systems
  • Cooling Towers


  • Chillers-Recip, Scroll, Screw
  • DX Systems
  • Walk In Coolers
  • Commercial Refrigeration
  • Condenser Units
  • Ice Machines
Custom Piping
  • Licensed Master Plumbers
  • Gas Piping Systems
  • Specialty Pipe Welding
  • Hydronic Systems
  • Process Piping
Equipment Maintenance

Unplanned HVAC/R equipment repair or replacement can derail even the most well-planned budget. A comprehensive preventive maintenance program has proven to reduce risk and operating costs by as much as 10-30%.  Preventive maintenance is maintenance that is regularly performed on equipment to lessen the likelihood of it failing. Initiating a preventive maintenance program reduces the chances of little mechanical problems becoming big problems. Thayer Corporation recognizes and acknowledges the need for preventive maintenance, and is committed to providing customized maintenance agreements throughout the State of Maine to customers both large and small. 

24/7 Repair Service
  • Large Extensively Trained Team of Technicians
  • 24-Hour Emergency Service
  • Cellular Dispatch
  • State Certified
  • State Wide Fleet
Control Systems
  • Building Controls & Automation
  • Temperature
  • Ventilation
  • Humidity
  • Refrigeration
  • Energy Management 
  • Hydronic
  • Pneumatic
  • HydroCarbon Monitor
Custom Piping
  • Licensed Master Plumbers
  • Gas Piping Systems
  • Specialty Pipe Welding
  • Hydronic Systems
  • Process Piping
  • MIG & TIG Welding
  • Programmable Plasma Center
  • Shear 30 Gauge 10 1/4″ X 10 Plate
  • Specialty Sheet Metal
  • Curb Adaptors
  • Custom Duct
  • Air Hoods
Process Piping

Lighting is an often overlooked, underappreciated aspect of  business. In reality, the importance of having the right commercial lighting is critical.  When considering the choices for lighting a commercial space, it is important to be able to determine which lighting best fits your space or use. Between initial costs, energy expenses, replacement costs, lumen output, and color rendering accuracy, choosing the ideal lighting system can quickly become overwhelming.

Thayer Corporation has devoted team members to offer you energy efficient lighting solutions. Whether your current lighting system needs repair or you want to do a complete lighting redesign, we’re here for you.

Career Opportunities


Hours Of Operation

Monday - Friday
7:00 a.m. to 5:00 p.m.
Always On Call 24/7

Saturday & Sunday
24/7 Emergency On Call Support

24/7 Emergency Service

Keeping your systems operational is our primary goal. 



Drop Us A Line

Don't be shy.  Let us know if you have any questions! 



Thayer Corporation Proudly Serves The States of Maine and New Hampshire