In the mid-1970's, Masi Plumbing & Heating was one of the largest plumbing and heating companies in southern New Hampshire, installing plumbing, heating and air conditioning in many new home developments throughout the greater Nashua area.

Early in Masi's history, Bob Sr. established a plumbing and heating store at 36 Otterson Street in Nashua. The store catered to the do-it-yourselfer and small contractor who required product and/or advice on installations. Business thrived and a second store was opened by Bob's sons in Milford, NH in order to cater to the developing communities of the Souhegan Valley. After the region's building boom in the '80s, the focus of Masi Plumbing & Heating switched from the new home market to service, renovation and bath remodeling. Its customer base transferred from builders and developers to homeowners. By the early '90s, the store on Otterson Street became too small for the company's growing remodeling business as additional space was required to effectively display the finer bath and kitchen fixtures and accessories available. While still maintaining the plumbing supply stores, Ed Boisvert implemented the company's first bath showroom by establishing Splash by Masi at 33 Main Street in Nashua. Splash originally opened as a small showroom in 1994 but quickly grew in size; from 600 to 1,200 square feet to its current size of 5,000 square feet. Splash offers southern New Hampshire and northern Massachusetts a highly diverse selection of fine decorative plumbing and hardware, offering top quality service with competitive pricing for all price levels.

In 1998, a third generation joined the family business as Bob Jr.'s son, Bobby, joined the leadership of Masi, refining the company's focus to full bath renovation, plumbing services and sales of mid to high-end bathroom products. In the fall of 2003, Masi opened its second Splash showroom, a 4,000 square foot facility, at 977 Elm Street in Manchester in order to better serve the greater Manchester area and northern New Hampshire communities.