Our Story
A family tradition of honest HVAC service, proudly serving Northern Colorado since 2014.
Built on Trust & Tradition
A Plus was established in 2014 by Darren Knoll of Berthoud, CO. With decades of experience in the HVAC industry, Darren aimed to provide the Northern Colorado communities with honest and reliable heating and air conditioning services.
In 2022, Darren was approaching retirement and reached out to a family member who had been in the same industry for 8 years. Zach Karre, cousin of Darren, was exactly who Darren thought would align with the values of A Plus.
In March of 2023, Zach took ownership. Zach gained a love for the HVAC trade at the age of 16 while working for a local company in Nebraska. After high school, Zach attended trade school at Mid Plains Community College, graduating as head of class, and continued his career in Lincoln, Nebraska where he learned the operations of a business.
Zach takes pride in providing honest and reliable services and a customer experience that is unmatched in the industry.
Milestones
Founded
Darren Knoll establishes A Plus Heating & A/C in Berthoud, Colorado.
Transition Begins
Darren approaches retirement and invites Zach Karre to continue the legacy.
New Ownership
Zach Karre takes ownership, bringing fresh energy and the same commitment to honest service.
30 Under 30
Zach is recognized as one of NOCO Style's 30 Under 30 for leadership and community involvement.
Our Values
Honest Service
We tell you what you need — not what makes us the most money. Transparent pricing and honest recommendations, every time.
Reliability
When we say we'll be there, we'll be there. Available 7 days a week, including evenings, to keep your home comfortable.
Community
We're invested in Northern Colorado. From our apprenticeship program with Roosevelt High School to local partnerships, we give back.
Meet the A Plus Crew
A dedicated team of professionals committed to keeping your home comfortable.
Zach Karre
Owner
Zach gained a love for the HVAC trade at age 16. He attended Mid Plains Community College, graduating as head of class, and took ownership of A Plus in March 2023. Named one of NOCO Style's 30 Under 30 honorees in 2025.
Kelsey
Office Manager
Keeps the operations running smoothly and ensures every customer receives a seamless service experience.
Jacob
Technician
Skilled technician dedicated to diagnosing and resolving HVAC issues with precision and care.
Grant
Apprentice
Learning the trade through our apprenticeship program, bringing fresh energy and dedication to the team.
Certifications & Partnerships
Ready to Stay Comfortable Year-Round?
Schedule your service today and experience the A Plus difference — honest, reliable HVAC care from a team that treats you like family.