Skip to main content

Top-Quality Replacement Windows Syosset, NY, Homeowners  

Do you feel frustrated with the lackluster appearance of your house windows? Perhaps their poor functionality is an issue as well. No matter the problem, one thing is certain, the professionals at Thermo-Seal Windows & Siding are here to help. Since 1985, our skilled and experienced team has proudly installed best-in-class house windows for homeowners throughout the Syosset, New York, area.

We offer our own line of custom windows, which are manufactured by our partner, Harvey Building Products. We also provide replacement windows that are sourced from Andersen and Pella—both companies are known for crafting strong, attractive, and energy-efficient windows. Additionally, we are an Andersen Certified Contractor, ensuring our team is trained to install these windows with unmatched precision.  

Our Windows

We offer replacement windows that are constructed from different materials, such as wood, thermoplastic, composite, and vinyl. Our windows are also available in a multitude of styles, such as:

  • Double-hung
  • Slider
  • Garden
  • Casement
  • Picture
  • Bay
  • Bow
  • Custom shapes

Our replacement windows are also:

  • Energy-efficient and can help reduce your heating and cooling expenses by up to one-third
  • Able to help lessen the infiltration of outdoor noise
  • A cinch to care for

We back our windows with a 100% satisfaction guarantee and a limited lifetime warranty, which covers defects or seal failures on all mechanical and vinyl components.   

Contact Our Team

For more information about our windows, contact Thermo-Seal Windows & Siding today. Our team looks forward to providing a virtual or in-home estimate for your project and going over the convenient financing options we offer to homeowners in Syosset, NY.

We make clients happy.

We Make it Easy

With customer service and craftsmanship that’s second-to-none, we make it easy
to achieve the home of your dreams.
Free, No Hassle Estimates Schedule a free in-home or virtual estimate. We’re here to help!
High Quality Products We offer the best products available, including our own brand of replacement windows.
Satisfaction Guarantee Our job is not done until you’re completely satisfied.

We've got connections.

We're certified by the industry’s leading manufacturers to offer a wide range of top quality options. View Our Credentials

Thermo-Seal Windows Siding & Roofing, Inc. is an A+ Rated BBB Accredited Business serving Westchester County, Rockland County, Nassau County, Suffolk County and Fairfield County. We offer multiple locations throughout the Tri-State Area to better serve our customers.

456 Sunrise Highway
Rockville Center, NY 11570
(866) 281-4567
Melville Office
68 South Service Road
Melville, NY 11747
(866) 281-4567
Rye Corporate Office
411 Theodore Fremd Avenue
Rye, NY 10580
(914) 925-3443
Stamford Office
263 Tresser Blvd
Stamford, CT 06901
(203) 663-3534