PRECISION WORK. FAIR PRICING. REAL PEOPLE
Keeping Raymond, NH and surrounding areas comfortable year-round with reliable heating and cooling solutions
MA/NH Saves Certified Heat Pump Contractor
NH Licensed Gas Fitters ensuring safe, efficient installations
EPA Certified technicians ensuring environmentally compliant service
Factory trained & certified in top brands including Mitsubishi, Bosch, Buderus, Rheem, Spacepak, Renai, Generac and more
Proudly serving Raymond, NH and surrounding towns
Discounts offered for all Military, Police, Fire, EMS & Senior Citizens
Our Services
Boilers
Furnaces
Water Heaters
Standby Generators
Ducted Central Heat & AC Systems
Ductless Mini Splits
Radiant Heating Systems
Complete Geothermal systems
Dual Fuel / Oil & Gas Conversions
Sheet Metal Fabrication
Commercial / Residential Maintenance Agreements
About Us
603HVAC is a family-owned and operated company proudly serving Southern New Hampshire. With many years of experience in both residential and commercial HVAC, we are committed to providing reliable, high-quality heating and cooling solutions tailored to our customers’ needs. As a local business, we take pride in supporting and serving our community with honest service, expert workmanship, and dependable care.
Hear From Our Customers
Ethan and crew have been INCREDIBLE. Two different properties we own ended up without heat during a recent snowstorm and he got them both up and operational as quickly as possible. Including picking up our phone calls at almost 10pm on a weekend. I can't say enough good things about them! Highly recommend!!
—Christina M. 01/26/2026
“Ethan and his team did an amazing job converting our home to natural gas, updating our hot water system (and many other projects!). They were extremely professional, thorough and explained every step along the way. 5 stars +++!”
— Laura T. Exeter, NH
“I recently switched from oil heating to propane for both heating and hot water, and I couldn't be happier with the service provided by 603 HVAC. Ethan, the owner, and his crew were exceptional. They ran a new gas line, set up all the ductwork in my attic, and installed a brand new gas furnace with a central A/C condenser unit outside--all in just two days!
I had a special request to keep all the ducts under the floor of the attic, and they were incredibly accommodating, doing a fantastic job with that. They also removed the old furnace and oil tank, which has freed up space for an entry room in my one-story house and more room in my garage where the oil tank used to be.
Before choosing 603 HVAC, I shopped around with other HVAC companies, and 603 HVAC was by far the best value. The professionalism, efficiency, and quality of work from 603 HVAC are top-notch. I highly recommend them to anyone looking for HVAC services. Thank you, Ethan and team, for a job well done!”
— Mark T. Chelmsford, MA
“90+ degree weeks in New Hampshire can be rare but this week was a brutal heat wave and our air conditioner broke on the first day. We spent an entire day calling any HVAC company to come and take a look at it and they were either booked out for weeks or only did emergency calls for their current customers. I called Ethan at 603hvac and he was just as busy as everyone else but he said he'd stop by on his way through town the next day to make sure I was ok and he did just that. He called first to see if we were all set and when I said I wasn't he was here in 10 minutes. He got our A/C back up and running in 20 minutes. Ethan and his team were so polite, respectful and knowledgeable. I truly appreciated them today and I highly recommend them to anyone with HVAC issues.”
— Kim M. Danville, NH
He did a fine job. In and out with minimal disruption. Everything immaculate.
—Jeffrey H. 02/02/2026
Very professional team. They do great work!
—Mark H. 04/22/2026
Always top notch service from scheduling to work performed. Always happy with 603!!!!
—Matt B. 04/18/2025
The whole team was great!
—Bill C. 04/22/2025
I woke up this morning to 5-degree temperatures outside and a furnace that wasn’t working. I called 603HVAC, and within an hour Zachary was at my home diagnosing the issue. He quickly identified the problem, obtained the necessary parts, and had my system up and running again. Zach was professional, knowledgeable, and took the time to answer all of my questions. From the initial phone call with Adrienne—who was pleasant and understanding—it was clear that 603HVAC is a top-notch operation. Earlier this year, I also called them for a mini-split issue, and they resolved it the same day. I highly recommend 603HVAC.
— Sean M. 01/21/2026
“Ethan and team are willing to take on the hard projects. His team did an excellent job replacing our whole-house air source heat pump (removed Daikin Altherma, installed Spacepak Solstice). The unit was newly released from the manufacturer and had a few functions not quite as expected; but he stuck with it to finish the project. The overall workmanship was very good. I have full faith and confidence he'll be here to address any issues that might arise. The unit is now running great and we look forward to 20 years of super efficient operation with the support from he and his team.”
— Ben B. Lee, NH
Called at 8:00am with no heat. Very professional and responsive. Fixed issue same day.
—Jim B. 02/07/2026
Ethan is knowledgeable and incredibly responsive! When we call we know we can trust that 603HVAC will get it done! Very grateful!
—Andrea K. 01/24/2026