If you haven’t seen our trucks around your neighborhood yet, we’re SumZero Energy Systems, and this is our seventh year in business. We started in 2019 believing heat pumps were the right answer for Massachusetts homes well before most people agreed, and we’ve spent every year since proving it. Over 2,000 homes across MetroWest now run on systems we designed and installed.

How we grew into the work

We began as a design, build and maintenance company, focused on getting heat pumps specified correctly and installed properly. In 2024 we opened our own service department, so that the homes we took care of stayed taken care of. This year we added licensed plumbing and electrical, and that decision had far less to do with wanting a bigger company than with something we kept running into on our own job sites.

Why we kept becoming the hold-up

Almost no heat pump project is only heat pump work. A boiler needs bleeding, an old oil tank has to come out, a heat pump water heater goes in, or a panel has to be updated before it can carry the new system. For years we had two choices whenever that came up. We could hand it back to you to arrange, or we could go find somebody willing to come out. Both slowed your project down, and both meant that the company you hired to manage the job had quietly stopped managing part of it.

What homeowners told us

Much of this came from listening to people who had hired other contractors. Their biggest frustration was almost never the heating system itself, which usually went in fine. What stayed with them was the subcontracted plumber or electrician who arrived having missed every planning conversation, didn’t know what the rest of the job required, and left behind work that didn’t match the standard of everything around it. We didn’t want to be those people. If our name is going on your house, we should be able to finish the whole job.

One company, one schedule

Today the same team that designs and installs your system also handles the plumbing and the electrical that come with it. Your panel upgrade, tank removal, water heater and piping belong to one plan, priced up front, carried out by people who were in the room when that system was designed. There’s nobody for you to chase. We want a project to finish as though we were never there, apart from equipment that works. Our pricing holds up as well, because when you control the whole process you aren’t paying another company’s markup or guessing at what the work involves.

Contact Us

You’re welcome to visit our Training Center in Holliston and see the equipment running before you decide anything at all. Assessments are free and come with no obligation. Call us at 508-965-0046 or visit sumzeroenergysystems.com. 

We serve Ashland, Bellingham, Franklin, Holliston, Hopedale, Medway, Mendon, Milford, Millis, Natick, Norfolk, Norwood, Upton and Wrentham.