Thermolock Manufacturing started out as a small local window manufacturer in Northern Michigan.  As the demand for high quality vinyl windows increased, Thermolock expanded its distribution to include Ohio and Indiana.

Today, Thermolock has moved its manufacturing headquarters to Cincinnati, Ohio, where it manufactures windows and doors out of a state of the art 100,000 square foot factory. Thermolock Vinyl Windows & Patio Doors can be purchased through distributors from Pennsylvania to Kansas and beyond.

The increasing demand for unique high quality windows will carry Thermolock into new territories in the future.