Air Conditioning & Heating in Fairfax, VA
We provide reliable heating and cooling services in Fairfax, VA. HVAC Unlimited keeps your home comfortable year-round with prompt expert AC repairs, replacements, and maintenance. Call today.
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The Locally Trusted HVAC Contractor
Looking for trusted HVAC service in Fairfax, VA? HVAC & Plumbing Unlimited is the local team homeowners count on for reliable AC repairs, heating system replacements, and seasonal tune-ups. From older brick homes near Old Town Fairfax to newer townhouses off Route 123 and family homes around Fair Oaks, our technicians know the unique comfort challenges of Northern Virginia living—humid summers, cold snaps, and everything in between. With upfront pricing, 24/7 emergency support, and decades of local know-how, we make sure your home stays comfortable all year long.
Need help now? Reach us online or call us at (571) 360-4520.
Heating & Air Conditioning Services We Provide in Fairfax, Virginia
Heating
Furnace Repair
Furnace Installation & Replacement
Furnace Maintenance & Tune-Ups
Boiler Repair
Boiler Installation
Boiler Maintenance
Heat Pump Repair
Heat Pump Installation
Heat Pump Maintenance
Hybrid & Dual-Fuel Systems
Air Conditioning
AC Installation & Replacement
AC Maintenance & Tune-Ups
Ductless Mini-Split Repair
Ductless Mini-Split Installation
Ductless Mini-Split Maintenance
Indoor Air Quality
Air Purification Systems
Humidifiers & Dehumidifiers
UV Air Scrubbers
Duct Cleaning
Dryer Vent Cleaning
Duct Repair & Sealing
Others
Airflow Balancing
Zoning Systems
Thermostat Installation
24/7 Emergency HVAC Service
Annual Maintenance Plans
Commercial HVAC Services
Why Fairfax Neighborhoods Depend On HVAC Unlimited
Fairfax homeowners don’t just need heating and cooling that works—they need a service team that shows up on time, treats their home with respect, and delivers solutions built for Northern Virginia’s unique climate. That’s why families across the area continue to trust HVAC & Plumbing Unlimited.
✔ Local expertise: We understand Fairfax homes—whether it’s a brick colonial with aging ductwork or a newer townhouse with hot upstairs bedrooms.
✔ Skilled technicians: Our team undergoes ongoing training to stay ahead of new technology, from high-efficiency heat pumps to ductless mini-splits.
✔ Honest service: Upfront pricing, clear communication, and recommendations based on your needs—not sales quotas.
✔ Safe and reliable work: Every installation and repair is completed to code and tested for long-term performance.
✔ Customer-first approach: From 24/7 emergency coverage for Comfort Club members to routine maintenance, we’re here whenever you need us.
For decades, our focus has been simple: combine technical excellence with personal care. That commitment to quality, honesty, and reliability is why Fairfax families continue to count on us season after season.
If your heating / AC unit has problems, call (571) 360-4520 now.
What to Do When Your AC Stops Cooling
Before you call, a few quick checks can save you a service visit — or at least help our technician arrive prepared.
Check these first
Thermostat
Confirm it’s set to cool, not fan-only. A thermostat accidentally switched to “fan” will blow air without cooling.
Air filter
A clogged filter blocks airflow and can cause the system to freeze up or shut down on a safety switch. If it’s visibly gray and thick, swap it out.
Breaker
Check your electrical panel for a tripped breaker on the AC circuit. Reset it once — if it trips again, don’t touch it and let us know when you call.
Outdoor unit
Make sure the condenser (the unit outside) is running. If it’s off or the fan isn’t spinning, that tells us a lot before we even arrive.
What happens when we arrive
1
Talk through what you’ve noticed
When did it stop cooling? Is it running constantly or shutting off early? Any sounds or smells? What you’ve observed helps narrow things down before we open anything up.
2
Test electrical components
We test the capacitor, contactor, and control board with a multimeter. A failed capacitor is the most common culprit on summer no-cool calls — it’s not something you’d spot visually, but it shows up immediately on a meter.
3
Check motor amp draws
We measure how hard the compressor and fan motors are working. A motor pulling too many amps is heading toward failure — catching it here prevents a more expensive breakdown later.
4
Measure refrigerant pressure
We connect gauges to check system pressures against manufacturer specs. Low pressure points to a leak — which needs to be found and fixed, not just topped off. This step also rules out refrigerant as the issue when pressures look normal.
5
Walk you through what we found
Before anything gets fixed, we explain what’s wrong, why it happened, and what it’ll cost. You approve the work before we start.
Call (571) 360-4520 directly for prompt AC service.
Air Conditioning Services
We install, replace, repair, and maintain all types of cooling systems in Fairfax, VA — central air conditioners, ductless mini-splits, and heat pumps. Whether you need a same-day fix or a full system upgrade, our NATE-certified technicians handle it all.
Same-Day AC Repair in Fairfax
When your system stops cooling, we diagnose and fix it fast. We work on all makes and models and carry common parts on every truck — most repairs are done in a single visit. Common issues include refrigerant leaks, compressor failures, faulty thermostats, and dirty coils.
Regularly replacing AC filters every 1-3 months is crucial for optimal performance and air quality in Fairfax’s varying climate.
AC Maintenance or Tune-ups
Getting your system serviced before summer hits is the best way to avoid a breakdown on a 95-degree day. We clean coils, check refrigerant levels, inspect electrical connections, and test performance — catching small issues before they turn into expensive ones.
AC Installation / Replacement
If your system is aging or struggling to keep up, it may be time to replace it. We assess your home’s cooling needs, recommend the right equipment, and install it correctly. Proper sizing matters — an oversized unit short-cycles and wears out faster than one matched to your home.
24 Hour Emergency Heating & AC Repair in Fairfax, VA
(for Contract Customers)
While we serve all customers until 10 PM, overnight emergency service (after 10 PM) is reserved for contract customers.
HVAC emergencies often strike at the worst times. At HVAC & Plumbing Unlimited, we’re prepared to handle heating and air conditioning emergencies in Fairfax, VA year-round. Our 24-hour service ensures prompt and professional repairs, regardless of the issue’s size.
See our financing and coupons!
Our experienced staff treats your emergency like our own, providing swift solutions to restore your comfort. Whether it’s a complete system failure or a minor issue, we’re equipped to manage all heating and AC emergency repairs with the same level of dedication and expertise.
Fairfax Heating, Boiler, and Furnace Repair & Installation Services
Installation & Replacement
We install and service a wide range of heating systems, including gas and electric furnaces, boilers, and ductless heating units. Whether you’re replacing an aging furnace, upgrading to a high-efficiency boiler, or adding ductless heating to a room that never stays warm, our team ensures the job is done right. We start with a full evaluation of your home’s size, insulation, and layout, then recommend properly sized equipment for safe, efficient performance.
- Gas & electric furnaces
- Boilers (steam and hot water)
- Heat pumps
- Ductless heating systems
Heating Repairs
When your heat cuts out, you need a fast, accurate fix. Our Fairfax technicians handle everything from furnaces with ignition failures and blower motor problems to boilers with leaks, low pressure, or faulty pumps. We service all makes and models and stock common parts to complete most repairs on the first visit.
Common repairs include:
- Furnace heat exchangers, burners, and ignitions
- Boiler leaks, circulator pump failures, and valve issues
- Noisy systems, uneven heating, or thermostat malfunctions
Maintenance & Inspections
Routine service helps your heating system last longer and run more efficiently. Our seasonal tune-ups check all critical components, clean and test your equipment, and identify small issues before they become big problems.
- Thermostat calibration and safety control testing
- Burner and heat exchanger cleaning & inspection
- Boiler water level and pressure checks
Call (571) 360-4520 for prompt service on any AC or heating system.
Proudly Serving Fairfax, VA
Fairfax is known for its small-town character surrounded by the bustle of Northern Virginia, with historic homes, brick colonials, townhouses, and newer planned communities all side by side. Each of these property types comes with its own comfort challenges—older homes may lack modern ductwork, while newer builds often struggle with hot upper levels or high utility bills. Our team understands these differences and knows how to match the right HVAC and plumbing solutions to each.
The local climate adds another layer of complexity. Summers are long, hot, and humid, which means air conditioners and heat pumps need to be sized and installed to handle heavy moisture loads. Winters bring cold snaps that can stress aging furnaces, boilers, and plumbing systems. Add in the tree cover and shaded lots common around Fairfax, and you’ll often see humidity lingering even when the temperature isn’t extreme.
That’s why homeowners here need more than just equipment—they need systems designed for Fairfax living. At HVAC & Plumbing Unlimited, we’ve spent years servicing homes throughout the area, from AC installations in older neighborhoods to emergency plumbing repairs during freezing weather. Whatever the season, our goal is to keep Fairfax families safe, comfortable, and confident in their home systems.
Local Reviews for Fairfax
Hector – Fairfax, VA
Robert Campbell, from HVAC unlimited, has been servicing my house hvac systems and our family systems for many years. Robert’s hvac services are always very professional and thorough. When any repairs are needed, we feel comfortable about his honest suggestions and prices. We have recommended HVAC UNLIMITED to our family and friends and Robert Campbell is an asset to his company!
Erik – Fairfax, VA
Jermaine was super knowledgeable of my building and was able to identify and repair the problem with my air conditioner in a very quick timeframe!
T – Fairfax, VA
Great job!
LISA – Fairfax, VA
Love that Jermaine is back with HVAC Unlimited.
Laura – Fairfax, VA
Jeremy was completely thorough when servicing my unit that had stop heating. He explained every step and it’s cost as he went along. I have used several service companies and never been this pleased. I will definitely use HVAC for every call in the future!
Other Services in Fairfax, VA
24/7 EMERGENCY SERVICE
If you’re having a home emergency, you don’t want to wait a minute too long. That’s why our technicians and plumbers are available to solve problems 24 hours a day, and that includes weekends and holidays. After all, things always break at inconvenient times.
AIR CONDITIONING REPAIR
Northern Virginia summers are getting hotter, and if your air conditioner isn’t keeping up, we’re here to help! Learn more about our fast and reliable AC repair services to restore your home’s comfort and keep you cool all season long.
AC INSTALLATION
Need a new air conditioner? We’ll help you choose the right system for your home and install it with expert precision. From energy-efficient upgrades to full replacements, our Lorton-based team makes sure your new AC is built to last and ready to handle the summer heat.
Furnace Maintenance
Give your furnace the professional care it needs before winter hits in Fairfax, VA. Our certified technicians perform detailed tune-ups that prevent breakdowns, improve efficiency, and keep your home safely heated all season long.
FURNACE INSTALLATION
Upgrade your heating system with expert furnace installation from HVAC & Plumbing Unlimited. We install high-efficiency gas, electric, and oil furnaces tailored to your home’s needs—backed by certified technicians, trusted Carrier products, and a 100% satisfaction guarantee.
CONVENIENT WELLS FARGO FINANCING
Money should never get in the way of your family’s safety and comfort. We’ve arranged special payment options through Wells Fargo Financing that let you start enjoying your new system or repairs right away and pay for it over several months.