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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

    $25 off any repair

    Valid at participating locations. Limit one per coupon per household. Coupon must be presented at time of purchase. Cannot be combined with any other offers or discounts. Some restrictions, taxes and fees may apply.
    Expires: 03/16/17
  • Protection Plans

    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 ComfortCollection™, protection plans designed to fit your home's needs.



    • 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.