❄️ Official Rankings
10 Best HVAC in Merrimack, NH (August 2026)
We compared 10 hvac serving Merrimack and Hillsborough County, New Hampshire, and ranked the top providers by verified reviews, ratings, and local reputation — 2,861 customer reviews in all.
The 10 listed below hold an average rating of 4.9 out of 5, led by Alpha Building Inspections. Updated for August 2026.
- HVAC ranked
- 10
- Average rating
- 4.9★
- Reviews analyzed
- 2,861
- Area code
- 603
Alpha Building Inspections
⭐ 5.0 · 2062 reviews
381 Daniel Webster Hwy, Merrimack, NH 03054
JMS Plumbing and Heating LLC
⭐ 5.0 · 223 reviews
11 Jakes Ln, Merrimack, NH 03054
A and C Mechanical LLC
⭐ 5.0 · 40 reviews
23 Fairway Dr, Merrimack, NH 03054
Artisan Plumbing & Heating, LLC
⭐ 4.9 · 51 reviews
579 Daniel Webster Hwy unit 1B, Merrimack, NH 03054
Jolt Electric & HVAC
⭐ 4.9 · 50 reviews
461 Charles Bancroft Hwy Unit A, Litchfield, NH 03052
TJO Contracting LLC
⭐ 5.0 · 15 reviews
2312 Columbia Cir, Merrimack, NH 03054
Advanced Quality Air
⭐ 4.8 · 20 reviews
442 Charles Bancroft Hwy, Litchfield, NH 03052
HVAC in Merrimack — FAQs
How do I choose the best HVAC company in Merrimack, NH?+
Compare local companies on verified reviews, confirm they service your equipment — furnace, heat pump, or central air — and check they're licensed in New Hampshire. Top-rated options serving Merrimack include Trolley Crossing Heating and Cooling and JMS Plumbing and Heating LLC. Ask about emergency availability for a New Hampshire winter.
How much does HVAC service or installation cost in Merrimack?+
Costs depend on whether you need a repair, a tune-up, or a full system replacement, plus your home's size, so Merrimack contractors quote after an assessment. For installations especially, get two or three quotes from top-rated local companies to compare.
How often should I service my heating and cooling system in New Hampshire?+
Most HVAC professionals recommend an annual heating tune-up before winter and an air-conditioning check before summer. Regular maintenance keeps the system efficient and helps catch small problems before they become expensive failures in a cold snap.
Which HVAC companies are top-rated in Merrimack, NH?+
By verified reviews, highly rated HVAC providers serving Merrimack include Trolley Crossing Heating and Cooling, TJO Contracting LLC, and JMS Plumbing and Heating LLC. Merrimack is in Hillsborough County (area code 603).
HVAC listed here serve Merrimack, Hillsborough County, and nearby ZIP codes including 03054.