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Mount Airy Heating & Cooling Experts

Always On Time...

  • ‘Round the Clock Availability

    No matter the hour, you can trust One Hour to be there to help you when you get hit with the unexpected.

  • 100% Satisfaction Guarantee

    We guarantee our materials, labor, and craftsmanship for up to two years from the date of your service.

  • StraightForward Pricing® Guide

    Before we start any work, we discuss your available options so you know exactly what you are getting and how much it will cost. No hidden fees!

  • Always On Time…Or You Don’t Pay A Dime!®

    We understand your time is valuable, so we promise to arrive at your home within the predetermined time window that you select, or your service call is free.

Get the Best Service Around

Our Happy Customers

Our Comfort Specialists are available to help, no matter the time of day. If you're in need of emergency services, we've got you covered 24/7.

  • “Larson is a great technician. Explains things thoroughly and is super friendly. The gentleman working with him was also great”

    - Lisa D
  • “Larson explained the issue and how he was going to fix it very clearly and understandably.”

    - Alison A
  • “My HVAC system started providing heat when cold air was requested. Tech was on time, friendly, and quick. Thoroughly checked all possibilities and determined root cause. Provided friendly ...”

    - Joe C | Westminster,
  • “Tyrell showed up on time and did very thorough work for us. He was friendly and knowledgeable. He was able to answer my questions and made good recommendations on the maintenance of our unit.”

    - Barbara C | Mt Airy,
  • “Gilmer did a great job on our HVAC unit. He was very personable, a good sport with the kids and dog, and most importantly, made sure I understood the problem, what he was doing go fix it, and all my ...”

    - Kaley L | Mt Airy,

Mount Airy HVAC Company

Heating & AC Experts Serving Frederick County, Montgomery County & Beyond

One Hour Air Conditioning & Heating® of Mount Airy has a long history serving the residents of Mount Airy, Frederick, Gaithersburg, and throughout the Washington DC area. We’ve been in business since 1949 and turned our focus to HVAC service in 1993. Our team has the same goal that we started with: making customers happy and comfortable through excellent heating and AC service. Every member of our team undergoes extensive training and is well equipped to solve any HVAC problem. Our vehicles are so well-stocked with parts that we can finish most jobs in one visit!

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100% Satisfaction Guaranteed

Special Offers

  • One Hour Air Conditioning & Heating® of Mount Airy Free Replacement Estimates Upgrade Today and Save on Your Energy Bills! One Hour Air Conditioning & Heating® of Mount Airy Expires: Dec 31, 2022 Print

Why Maryland Customers Love Our HVAC Services

Even though we operate under the name of a nationally-recognized HVAC company, we’re a proud local business based in Mount Airy. Our team back all their jobs with amazing guarantees that make sure we’re always on time, and we always do the job right the first time. To be as transparent as possible, we also have a StraightForward® pricing guide so you’ll know the costs of all our heating and AC services before we perform them.

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Frequently Asked Questions

  • What does the One Hour mean in your company name?

    The ‘One Hour’ in our company name indicates our guarantee to be at your home in the predetermined window quoted when you set your appointment. If we do not show up within that window, your service call fee is waived.

    1. Express Appointment: This is an appointment that is scheduled during a specified one-hour time slot. You are promised that a technician will arrive at your home within this one-hour time window. You will also receive a call when the technician is en route to your home.

    2. Reserved Appointment: This is an appointment that is scheduled during a specified, two-hour time slot. You are promised that a technician will arrive at your home within this two-hour time window. You will also receive a call when the technician is en route to your home.

    3. Standard Appointment: This is an appointment that is scheduled during a specified four-hour time slot. You are promised that a technician will arrive at your home within this four-hour time window. You will also receive a call when the technician is en route to your home.

    4. Stand-By Appointment: This appointment is for overflow situations. This appointment will not have a specified time. You will receive a call when the technician is en route to your home.

    5. Emergency Appointment: This appointment is for an unspecified time after normal business hours Monday – Saturday and all day on Sundays/Holidays. Calls are dispatched in the same order they are received. You will also receive a call when the technician is en route to your home.

  • Do you service emergencies after-hours?

    Yes, we offer emergency services 24-hours a day, year-round.
  • How much will my service cost?

    The size and complexity of your HVAC issue will determine the cost. Because our trained, licensed HVAC technicians must diagnose the issue before we are able to quote you an accurate cost, we require an appointment to be set to complete a diagnostic on your system. Once the diagnostic is complete, your One Hour(R) technician will walk you through all costs using our Straightforward Pricing(R) Guide so there are never any surprise fees.
  • How often should I service my HVAC system?

    It’s ideal to service your cooling system each spring and your heating system each fall to ensure you find small issues before they become big problems.
  • How often do I need to change my HVAC filter?

    Your filter should be changed every one to three months, depending on conditions in your home and your region’s climate.
  • Do you offer purchase financing?

    We work with several lending partners to ensure our customers are able to restore comfort in their homes. Ask your technician about your financing options.
  • What are the advantages of a smart thermostat?

    Smart thermostats learn a household's patterns and adjust heating and cooling according to when a home is occupied, give homeowners the ability to control the thermostat remotely, and enable homeowners to reduce their energy use, saving you money.
  • What is a SEER Rating?

    The SEER (seasonal energy efficiency ratio) is a measure of the efficiency of your heating and cooling system.The higher the SEER rating, the more efficiently a unit operates. The SEER rating of any given unit can range anywhere from 13 to 21.

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