Business Details
39 Years
experience
Emergency
services
Your Trusted HVAC and Plumbing Experts in New Hampshire
Founded in 1987, Granite State Mechanical Services (GSMS) has built a legacy of excellence in HVAC and plumbing solutions across New Hampshire. As a family-owned business, we combine over 35 years of industry expertise with a commitment to innovation, ensuring every project meets the highest standards of quality and reliability. Our team of certified professionals specializes in residential and commercial heating, cooling, and plumbing systems, offering comprehensive services from emergency repairs to energy-efficient installations. We prioritize customer satisfaction through transparent communication, competitive pricing, and personalized service tailored to each client's unique needs. Our dedication to the community is reflected in initiatives like 'We Heart Local,' where we donate monthly to New Hampshire-based nonprofits.With advanced diagnostic tools and a proactive approach to maintenance, we ensure systems operate at peak efficiency year-round. Our leadership team, including founder Mark Downing and second-generation leaders Zak and Jack Downing, brings decades of hands-on experience and a passion for mechanical excellence. We stand by our work with industry-leading warranties and a 100% satisfaction guarantee. By investing in continuous training and cutting-edge technology, we remain at the forefront of HVAC and plumbing advancements. For every homeowner and business owner in New Hampshire, GSMS is the trusted partner for comfort, reliability, and community stewardship.
Services
AC Repair
Furnace Installation
Water Heater Replacement
Mini-Split Heat Pump
Ductwork Services
Boiler Installation
Plumbing Maintenance
Smart Thermostat Installation
Emergency Repairs
Water Filtration Systems
Details
- Year established: 1987
Highlights and features
- Family-owned with 35+ years of local expertise in HVAC and plumbing.
- Industry-leading WOW Warranty on all installed systems.
- Smart Monitoring technology predicts and prevents system issues.
- Active community involvement through the We Heart Local initiative.
- 100% satisfaction guarantee with transparent pricing and honest service.
What people say
Excellent work
Quick response
Efficient service
Great reviews
Highly recommend
Services
AC Repair
Our certified technicians diagnose and fix all AC issues, from refrigerant leaks to compressor failures. We use advanced tools to restore cooling efficiency quickly, ensuring comfort during hot New Hampshire summers. Emergency services available for urgent needs.
Furnace Installation
We install high-efficiency furnaces tailored to your home's size and climate needs. Our team ensures proper sizing and ductwork integration for optimal performance, reducing energy costs and enhancing winter comfort.
Water Heater Replacement
Upgrade to reliable tank or tankless water heaters from trusted brands. Our installation includes energy efficiency analysis and lifetime maintenance support, ensuring consistent hot water supply for households.
Mini-Split Heat Pump
We provide energy-efficient mini-split solutions for homes without ductwork. Our installations include zoning options for customized temperature control, combining heating and cooling in one compact system.
Plumbing Maintenance
Regular maintenance plans prevent leaks and extend plumbing system lifespans. Services include pipe inspections, water pressure checks, and drain cleaning to maintain optimal household functionality.
People
Mark Downing
Owner
With 44 years in HVAC and 35+ leading GSMS, Mark founded the company on craftsmanship values. He prioritizes quality installations and community involvement, ensuring every project reflects GSMS's standards.
Zak Downing
Director of Operations
Zak oversees daily operations and community initiatives, combining business expertise with hands-on project management. He champions GSMS's family culture and local giving programs since joining in 2011.
Jack Downing
Director of Service
Leading the service team for 7 years, Jack focuses on honest repairs and technician training. His mechanical expertise ensures every service call meets GSMS's high standards for reliability.
Adam Phelps
Service Specialist
With 30 years at GSMS, Adam specializes in precision installations. He emphasizes future serviceability in every project, mentoring technicians to maintain GSMS's reputation for technical excellence.
Gina Zafirakis
Client Experience Specialist
Gina manages client interactions with a focus on transparency. Her background in medical fields informs her approach to customer care, ensuring clear communication and satisfaction from consultation to completion.
Questions
What areas do you serve?
We serve all of New Hampshire, including Manchester, Nashua, Barrington, Merrimack, and Hooksett.
Do you offer emergency services?
Yes, we provide emergency HVAC and plumbing services for club members outside regular hours.
What financing options are available?
We offer 0% financing for new system installations during select promotional periods.
Are your technicians certified?
All our technicians hold state-required licenses and undergo continuous training in the latest HVAC and plumbing technologies.
What warranties do you provide?
Our WOW Warranty covers labor on installed systems, with terms varying by manufacturer and service type.
How can I schedule a service?
Book online through our website or call 603-424-8258 to schedule same-day or emergency appointments.
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Reviews (1)
Joelle Lanteigne
Dec 31, 2017
Report
GSMS was so helpful in dealing with our frozen pipe! Thank you again for helping us get our heat back in the freezing weather this week! Highly recommend!
