SumZero Energy Systems

SumZero has been great to work with on this rather complex project. From Paul's communication to Marcelo's great installation leadership, and Daniel's final adjustments this was executed with precision, great communication and quality. I looked at several options, probably had 3-4 other quotes, various vendors, Paul was the only one who understood that I needed an extra zone split and embedded that into the proposal. His team further revised the details during the install to optimize air flow. When COVID-driven supply chain difficulties got in the way, Paul kept us informed and was able to exceed his commitments. Sarai also guided us to a 0% 84-month loan in a couple of days, and promptly refunded deposit money not covered by it. We are excited to have our new Bosch Heat Pump and looking forward to many years of fine operation!

Illija and his crew were great. They were vastly less expensive than three other quotes, yet did top quality work. They were very professional and respectful of COVID constraints, and arrived exactly when they said they would (which was a great sign for how they were going to handle the install). I rarely post reviews, but when a small company does such outstanding work for such a great price, I feel compelled to let others know.

David and Wandersen have an amazing team! I have never worked with a more professional, knowledgeable and courteous team before. Every single person that works with Sum Zero was impressive. They were willing to answer all of our questions, provide accurate quotes and were always open to additions as the jobs moved forward. I welcomed them in my home for a week and a half of work and would do so again in a heartbeat. You cannot go wrong with hiring Sum Zero!

Great experience with this company. Interviewed three other companies. I worked with David at SumZero --and decided to go with them because he took the time to understand what I needed. Their pricing is very competitive and transparent. So you don't have to guess as to what is not included-- something that can't be said of some of the other companies I interviewed. I also liked that David made it easy for me to understand the technical jargon which ultimately gave me confidence that the final system configuration was best suited for our needs. He was very flexible throughout the entire process from start to finish. David also ensured the system qualified for the MassSave 0% energy loan and maximized the available rebates--which he is helping me to secure. The crew they sent out to install the system was very pleasant, respectful of our home, and very hard working. When the system was tested and ready to go online, SumZero had a technician onsite to show us how to operate the system. We love the Mitsubishi mini split system--it is amazing. Great experience from start to finish with SumZero. Totally recommend them without reservation.

Amazing experience to work with Ilija and his team. They were much less than two other quotes and in my opinion were worth double what we paid as they made sure everything was perfect. I can be a real picky person. But in the case I had to write a review and say amazing job done!!

very timely, efficient, and professional

These guys were fantastic. Given the Covid 19 pandemic they did all the prep work with me on video chat. I was given a number of options and recommendations. I got several quotes and they had the best price. Everything was installed with care, on time, and at the quoted price. I would gladly work with them again.

Very professional and honest! The sum zero team did an excellent installation on new heating system. Highly recommend them!

Excellent!! really impress with the owner. Gave though about our project. Very smooth working with him. Had a can do attitude and finish in a timely way.

It was great. He took care of everything and answer all question. Help with different options. The work was exactly what the quote came too.

They're most professional, they're great at what they did, attentive, easy to work with and very competitive price.

It was fantastic, professional, friendly, they put attention to detail.