Our Story
Our goal has always been to educate, support, and help professionals deliver better HVAC systems.
RST Thermal was founded in 1989 by Richard Trethewey—a fourth-generation plumbing and heating professional with lifelong roots in the trade. Drawing on that heritage, Richard created a new kind of HVAC manufacturer’s representative: one that prioritizes systems thinking, hands-on education, and long-term energy efficiency.
From the beginning, RST Thermal has represented high-performance HVAC products backed by technical support and real-world knowledge. Our team works closely with contractors, engineers, wholesalers, and homeowners to match the right equipment with the right application — especially in the older homes and challenging climates of New England.
As the industry has evolved, so has RST. We’ve expanded our services across Massachusetts, Rhode Island, Connecticut, New Hampshire, and Maine, and introduced hands-on training programs, a consulting lab, and one of the most trusted support teams in the region. Richard’s passion for teaching — seen nationally through his role on This Old House — continues to inspire how we serve our clients every day.
Today, RST Thermal remains committed to empowering HVAC professionals with smarter solutions, better tools, and a deeper understanding of the systems they install.
Where Experience Drives Results
At RST Thermal, experience is more than time served — it’s the foundation behind every decision, recommendation, and relationship we build. Our team combines technical knowledge with real-world problem-solving to support contractors, engineers, and distributors across a wide range of project types. From navigating system compatibility in older homes to helping spec high-performance solutions for commercial applications, we show up ready to help professionals succeed. The depth of our experience means we know how to adapt, communicate clearly, and move projects forward with confidence — because in this industry, the right insight at the right moment makes all the difference.
Key Capabilities
- Reliable Technical Support 100%
- Manufacturer-Trained Product Knowledge 100%
- Commitment to Energy Efficiency 100%
Team Members
Evan Trethewey
President
Richard Trethewey
Vice President
Maryellen Hickey
Operations Manager
Rich Bialobrzewski
Engineered Products Division Consultant
Mark Toth
RST Representative
Kevin Bergeron
RST Representative
Alex Toth
RST Representative
Dylan Beauregard
Inside Sales/Technical Support
What We Offer
Our Services
Our team provides comprehensive sales and technical support to HVAC contractors, wholesale distributors, engineers, architects, and homeowners. From product selection to detailed project specifications, we work closely with our clients to ensure systems are properly matched, installed, and optimized.
Products
Project Design & Specification
We assist with detailed system design and layout for commercial and residential projects. Our experience ensures that equipment is matched properly and performs efficiently from day one.
Training
Hands-On Product Training
RST Thermal hosts in-person training sessions throughout the year, helping HVAC pros stay up to date with the latest technologies, installation techniques, and code compliance.
Support
Technical Sales Support
We work directly with contractors, distributors, and engineers to recommend the right products for each job. From system selection to project specifications, our team is here to help you succeed.
Visit Our Showroom
Our 1904-mill headquarters in Fall River now houses a full-scale HVAC “comfort showroom” and training center. Inside, you’ll find radiant panels, ducted and mini-duct air handlers, VRF, geothermal, air-to-water heat pumps, fresh-air systems, and more—mounted and plumbed so you can examine real components and layout options side by side. Contractors and distributors refine installation techniques, architects and engineers explore design choices, and homeowners can visualize equipment before work begins.