SumZero Energy Systems

David and his crew were fantastic. Very friendly group of folks, super knowledgeable. I didn't feel like I was being upsold or sold something I didn't need.

We lost heat / hot water right as the cold season was starting. They paid an incredible amount of attention to detail, were extremely responsive and most importantly were helpful to my family in a time of need.

Daniel - "DL" - ran the crew that was at my property. David and Ilija checked in on a daily basis so you never felt abandoned after the sale. It was white glove service through and through.

I can't say enough positive things about them.

The Sum Zero team was exceptional- starting with Paul Jameson who was prompt in response, knowledgable and great communication. We got 4 other bids on the job and Sum Zero easily rose to the top. The installation crew were very professional, came on time and asked questions to ensure they were satisfying all our needs. Following the installation, we had a few additional questions about the thermostat- they actually came to the house the next day to walk us through everything again to ensure we were happy. They even submitted the paperwork for MassSave rebates. Any time we call, they deliver. Customer First attitude. Highly recommend.

Working with David, Sarai and SumZero was one of the best experiences I've had working with any home renovation comany!

We hired SumZero to update our HVAC system with heat pumps. They replaced our existing ducted A/C system and installed supplementary ductless heads to help cover our heating needs.

The things that impressed me most about SumZero was:

1. The estimate process. David talked to us about our goals and presented 4 different options are different price points and let us think about it and make adjustments with no pressure and quick responses!

2. Going above and beyond! SumZero completely handled the process of applying for relevant rebates and zero-interest loans offered by the state. They also coordinated removal of our old oil furnace and tank, even though they don't do that themselves!

3. The price was excellent. I got several estimates, and SumZero's price was very fair, and combined with state incentives, made it possible to completely update our system!

We have been through the end of one winter and the hottest part of summer, and so far the system is working perfectly and we are very comfortable!

It was a pleasure bringing in SumZero to install heat pumps and an HVAC ducted system into our home. Their customer service was responsive and and considerate and their installation crew was professional, clean, and creative. We had a complicated setup in our house, lots of windows, and space constraints, but the SumZero team did a great job coming up with a solution that worked for us. Highly recommend!

Sumzero installed a new heating and AC system in my house in September of 2021. As I stated in my previous review, they did a 5 star job. The new system works fine. Sumzero does not offer maintenance plan yet, so I hired another company to do the AC tune-up this year. They did not perform tune-up, just checked my AC and recommended additional costly services. I called Sumzero. Daniel came the next day. He was knowledgeable, detail oriented and friendly. He did an excellent job. Performed tune-up, cleaned entire system, and checked for leaks. Sumzero takes care of their customers, this is a company you can trust! I highly recommend Sumzero!

Working with SumZero was one of the best experiences we’ve had with a contractor, and we have worked with many trades people while renovating homes over the years. We used them to install heat pumps and insulate our attic and basement. David Sampaio is knowledgeable and gave good advice on the most efficient system to install. The installation crews came on time and had us up and running after just a day. They took into account a few surprises without increasing the price. Finally, they took care of submitting the rebate paperwork for us and helped with the HEAT loan process. Highly recommend.

David and his team did a wonderful job installing mini-splits for our entire home. They were punctual, knowledgeable, responsive and highly professional through the entire process of quoting through installation. They seemed to have a deeper understanding of the systems than their competitors delivering a more efficient system at a better value. We’re very happy with our mini-split system!

I've hired SumZero Energy Systems several times. They installed a new boiler and water filtration system and 4 ductless heating & A/C units. The service has always been professional, the workers are hard working, they clean up when they are done and they are genuinely interested in making sure the customer is satisfied with the job. I highly recommend them.

SumZero Energy Systems was outstanding!! I had a new ducted heating/cooling system installed in my attic along with a ductless unit for a large living space. Paul was so incredible! He answered all of my questions (there were many) and guided me through the entire process along the way. I knew what to expect and there were no surprises. I highly recommend Paul and his team to anyone looking for this type of service. Truly a pleasure!!

David and his team are fantastic. My furnace went on the coldest day in March, they were here the next day to install a new furnace. David was so nice, talked me through options, financing, and what to expect. I would highly recommend this company for any type of heating/AC issues or installations. They are the best!