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Ashburn 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.

  • “Our new four-panel system is perfectly suited to our needs, was reasonably priced and works like a charm. I especially like the interface they use that can show us power production in realtime and over the life of the system.”

    - Nick
  • “Their equipment is first-rate, prices are extremely competitive and their service is top-notch. No reason to look elsewhere.”

    - G.B.
  • “I will happily promote Modern Mechanical and their fine crews to my friends and neighbors and when I need my next upgrade I will call upon them once again without hesitation.”

    - Dave C.
  • “We were more than impressed with the professionalism of this company and its employees. We need to replace the other a/c unit and without hesitation, we will be calling Modern Mechanical.”

    - Danielle W.
  • “I called Modern Mechanical directly because the work they’ve done for me previously has been so terrific. Highly recommended to anyone needing a plumber in the NOVA area.”

    - Anne M.

Ashburn HVAC Company

Trusted HVAC Repair in Leesburg, Ashburn & Northern Virginia

One Hour Heating & Air Conditioning® of Northern Virginia is dedicated to providing the best value and customer service in Ashburn, Leesburg and all throughout Northern Virginia. One Hour isn’t simply our company name; it’s a promise to value your time. We stand by our craftsmanship and products because your family’s comfort is our top priority. We respect and value our customer’s time, so we guarantee our HVAC repair technicians will arrive on time to address your heating and air conditioning needs: like our motto says, “Always On Time…Or You Don’t Pay a Dime.”® We offer a 100% satisfaction guarantee for up to two years after your heating or AC service.

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100% Satisfaction Guaranteed

Air Conditioning & Heating Service in Ashburn

Northern Virginia HVAC Technicians Guarantee Our Work

Whether you need routine maintenance, a heater replacement, or air conditioning repair, our team is ready to help. Our technicians are licensed, trained, and skilled to handle any AC and heating, regardless of how big or small. For your peace of mind, our technicians are background checked and drug-tested. When you hire our team, you can rest assured that we will provide you with high-quality work and excellent customer service. Reach out to our Ashburn HVAC team today for an estimate!

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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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