Call 24/7 for emergency service 800.574.1725

Gaithersburg - HVAC Technician

Your local One Hour Heating & Air Conditioning has been serving the Carroll, Frederick, Howard, Montgomery, and Washington Counties area since 2000. We promise prompt and professional service to all of our customers. "Always on time, or you don’t pay a dime."™ We look forward to solving all your heating and air conditioning repair, installation and service needs. Call us now to schedule an appointment.
To visit our local Heating & Cooling Website Click Here.
2707 Back Acre Circle Mount Airy, Maryland 21771 License Number: 4818
Available 24/7

    Our company was established in 1949 building custom homes and remodeling in the Montgomery County area.  In 2000 we re-directed the company to specialize in residential air conditioning and heating service and replacement.  Our team continues to strive to become the most customer oriented service company in the county.  We  to do this through on-going training in communication skills and technical procedures. 

    Keeping abreast of new product knowledge in the HVAC industry so we can provide the homeowner with options to keep their homes comfort in severe weather. Still family owned and operated; we pride ourselves on providing excellent service for you-our customer. 


Gillian Collins - Owner - Vice President

Raised in Gaithersburg and received a degree in Computer Science/accounting from Montgomery College. Gillian worked at HHS/NIDA and Montgomery College as a computer systems analyst for 15 years. She joined her husband, Larry, in the business in 1989. Gillian’s passion, other than her family, is plein air painting. She has won numerous awards and sells her work at local galleries and art shows.

Larry Collins - Owner - President

Raised in Gaithersburg and received a degree in Microbiology from University of Maryland. Took over his father’s building/remodeling business in 1979 and expanded the company to service residential plumbing and water treatment. Larry holds a Master HVAC, Master Plumbing and Journeyman Electrical licenses. He enjoys spending his spare time target shooting and go-carting with his 3 children and grandsons. To relax his takes walks with his wife, Gillian, of 34 years.

Terry Fisher - Owner - General Manager


    Central and Western Maryland: 301.515.1001

    One Hour Air Conditioning & Heating is the residential expert in Central and Western Maryland.  We offer top-notch, craftsman installation, warranties, and One Hour Air exclusive guarantees.  We also specialize in all aspects of Indoor Air Quality including electrostatic filters, UV lights, Humidifiers, and more.  Our highly trained service technicians provide an unparalleled service with straightforward pricing.  We are available 24 hours a day, 7 days a week, 365 days a year including holidays!  Family owned and operated.  Family owned and operated.  Up to 60 Months No Interest Financing on HVAC Install!!!


    • Air Conditioners
    • Air Handlers
    • Boilers
    • Ductwork
    • Furnaces
    • Heat Pumps
    • Indoor Air Quality
    • Maintenance Agreements
    • Thermostats
    • Duct Cleaning
    • Geothermal
    • Tankless Water Heater

    • Barnesville
    • Bethesda
    • Brookeville
    • Cabin John
    • Chevy Chase
    • Clarksburg
    • Frederick
    • Gaithersburg
    • Germantown
    • Hagerstown
    • Ijamsville
    • Kensington
    • Middletown
    • Mount AIry
    • Olney
    • Poolesville
    • Potomac
    • Rockville
    • Silver Spring
    • Carroll, Frederick, Howard, Montgomery, and Washington Counties

    We're sorry, but looks like we don't have any special offers listed for your location at this time.  Please call your local One Hour Heating & Air Conditioning at 800.574.1725 to see if any new offers are available for you!

  • Home Comfort Collection™: Enroll now and have one less thing to worry about!

    Your home's heating and air conditioning systems keep you comfortable but you really only notice them when something goes wrong.

    At One Hour Heating & Air Conditioning, we know that every home owner and every home itself is different. As a service partner of Direct Energy, we are proud to offer the Home Comfort Collection, protection plans designed to fit your home's needs.

    The right plan for every home.

    New heating & cooling system. But for how long?

    Regular maintenance of your air conditioning and heating system is crucial in helping increase its lifespan and reduce energy bills and the chance of breakdowns. Protect your system with the Heating & Cooling Maintenance Plan.

    A heating or cooling problem is always an emergency.

    Problems with your heating or cooling system can be scary, stressful and even dangerous during months of extreme weather. Our Heating & Cooling Repair & Maintenance Plan provides worry-free coverage for inconvenient repairs. We can get your heating or cooling equipment back up and running quickly, safely and efficiently.

    Your HVAC system is vital to your home's comfort.

    The age of your heating and cooling systems isn't the only factor to consider in deciding when to replace these systems. If your system is starting to break down more frequently, it may be time to replace it. This is when you truly need the Heating & Cooling Repair & Maintenance PLUS plan.

    Protection Plan Benefits 

    Enroll Now

    Click here for more info!

    The Direct Energy Heating and Cooling Essentials Plans ("Plan") are provided by Home Warranty of America, Inc., We are Direct Energy's service partner in performing various services under the plan, but if for any reason a One Hour™ contractor is no longer available, Direct Energy will arrange for another qualified heating and air conditioning contractor to provide services under the plan. Customers must sign up for 1-year commitment (the "Initial Term"). There is a 30-day waiting period before repair coverage begins. Upon expiration of the Initial Term, the Plan will automatically renew at the then current standard rate and terms unless the customer opts out of the auto-renewal option in writing by mail at P.O. Box 850, Lincolnshire, IL 60069 or by email at Sales tax will be added in select states. To obtain a full copy of the Plan terms and conditions, which set forth coverage limitations and exclusions, call 1-855-334-3577. 

    Copyright 2014 Direct Energy Marketing Limited. Direct Energy is a trademark of Direct Energy Marketing Limited, used under license.



    • Stimulus Package Pays off for Carroll. Frederick, Howard, and Washington County Homeowners

      Up to $500 tax credit available to qualified homeowners like you!  Ask how you can cash in and also have a more efficient heating and air conditioning system for your family.

A family of home services:

Strong partnerships and a national support system.

Independently owned and operated.