In 1969, API of NH & Delta T was born out of a desire to provide both quality service and top value in heating and cooling products.

That goal has remained at the forefront of business and our distributorship now is proud to be a New England industry leader all these years later. We also have become part of Marcone Group, North America’s largest parts distributor. This gives our customers access to parts for plumbing, appliance repair, pool and spa, and commercial kitchens. Marcone’s nationwide distribution network provides access to a full catalog of parts with same-day shipping and next-day delivery to 93% of the U.S.

We remain a Master Distributor of premier Rheem HVAC product lines. The products we sell provide heating or air conditioning for local homes, restaurants, retail centers and more.

API of NH also has taken on the energy challenges of the future by offering the most energy-efficient product lines on the market today. Whether it’s hydronic heating, geothermal or solar power, you can count on us for products that use less electricity and save money year after year.

At API of NH, we believe your success is our success. That’s why we see every customer as a partner, offering innovative programs and business solutions that drive prosperity.

You are invited to join the family of companies already enjoying success through a partnership with API of NH. We look forward to serving you.


Robert Engel Sr., Stephen Engel, Bob Engel, Benjamin DeCarli,
Anthony Mangano, John Levesque, Don Lelievre, Ed Doherty, Billy Engel



When you work with API, you can be assured of two things: quality products and top-notch customer service. We are here to make HVAC contractors successful, so we focus on putting the customer first. Plus, our expertise in hydronics and sheet metal fabrication provides a well-rounded partner for your business.

We also offer:

Certified Technical Support – From system design and application to heat load calculations, you can rely on our experts for assistance with your project.

Same-Day Quotes – We know that time is of the essence for you and your customer. That’s why we offer same-day quotes to keep your project moving and on schedule.

On-Demand Delivery – With nearly 20 company-owned vehicles in our fleet, we guarantee same-day, on-demand residential and jobsite deliveries.

Training – When you are better, we are better. That’s why we offer top technical, business and sales training classes twice a year, taught both by industry experts and in-house trainers.