Whole-system duct and dryer vent check with before-and-after photos - you see exactly what came out of your vents
That "$99 whole-house special" is a bait ad - the real number appears once they are in your hallway, or the "clean" is a shop-vac at the register. We photograph the inside of your ducts before and after instead.
Before
After
Before
After
Before
AfterTrusted Duct Repair & Sealing for Leesburg Homeowners
Most Leesburg homes built between 1995 and 2010 lose 20 to 30 percent of conditioned air through leaks in the ductwork before it ever reaches the registers. CleanRun Air Duct Cleaning Leesburg offers our Duct Repair & Sealing in Leesburg and throughout Loudoun County with written prices delivered before any work starts, documented photo records of every duct run, and the 365-Day Done Right Promise backed in writing on every job. Since 2013, we’ve served over 52,000 homes with the same protocol: photograph the condition, quote the scope in writing, complete the repair, photograph the result.
Leesburg’s freeze-thaw cycles and humid summers stress ductwork in ways that show up as uneven temperatures, dust streaks near ceiling registers, and utility bills that climb without explanation. We see this pattern regularly in neighborhoods like Lansdowne, Woodlea, and the historic district near Wirt Street, where original metal ducts have separated at seams or flex duct has sagged at elbows. Our crews carry Rotobrush inspection cameras and mastic sealant rated for residential HVAC pressures, and every technician is background-checked and uniformed under Haven Standard Clause 3: Verified Crews. Call (571) 487-7204 for a free estimate with a written price before we remove a single panel.
What Our Duct Repair & Sealing Service Includes
Duct Sealing
Duct sealing closes the gaps, separations, and pinhole leaks that allow conditioned air to escape into attics, crawl spaces, and wall cavities. In Leesburg, we find the worst leakage at plenum connections (the central distribution box where the main trunk meets the furnace) and at register boots where drywall meets metal. CleanRun technicians seal these points with mastic compound or foil-backed tape rated for temperature cycling, then pressure-test the system to verify the seal holds under operating conditions. Every sealed joint is photographed before and after, and the images are delivered with your job record.
Flex Duct Repair
Flex duct, the ribbed plastic tubing common in Leesburg homes built after 1985, collapses at bends, tears at hanger points, and disconnects entirely when the plastic collar degrades. We replace damaged flex runs with new insulated duct sized to the original CFM (cubic feet per minute) specification, secure them with metal straps at 4-foot intervals, and seal each connection with a mechanical clamp plus mastic. In South Riding and Lansdowne, we’ve found entire flex runs draped across attic insulation, delivering air nowhere. Our repair restores the designed airflow path and is photographed at every connection point.
Metal Duct Repair
Galvanized steel ductwork, standard in Leesburg homes built before 1990, corrodes at low points where condensation collects, separates at longitudinal seams, and rattles when supports fail. We repair metal ducts by cutting out corroded sections, fabricating replacement pieces from matching gauge steel, and sealing with mastic rated for metal-to-metal joints. For separated seams, we install drive cleats or screw-strip reinforcements before sealing. The repair is pressure-tested and photographed, and we note any systemic corrosion that suggests the trunk line may need sectional replacement in the future.
Duct Insulation
Uninsulated or degraded duct insulation in Leesburg attics allows summer heat to warm cooled air and winter cold to steal heated air before it reaches your rooms. We install fiberglass duct wrap with vapor barrier (R-6 minimum for attics, per current energy code) or replace damaged insulation on existing flex runs. In homes near the Potomac with higher humidity, we check for condensation staining that indicates the vapor barrier has failed. The insulation is secured with metal pins and speed washers, taped at seams, and photographed to confirm full coverage.
Mastic Sealant Application
Mastic is a water-based, fiber-reinforced compound that remains flexible after curing, making it superior to duct tape for sealing joints that expand and contract with temperature changes. We apply mastic with a brush or caulking gun to all accessible joints in the duct system, including plenum connections, trunk-to-branch transitions, and register boots. In Leesburg’s older homes with multiple previous HVAC contractors, we often find layers of failed tape over still-leaking seams; we remove the tape, clean the surface, and apply mastic to bare metal or duct board. The application is photographed to document coverage.
Air Leak Repair
Air leak repair addresses the unintended pathways that connect your duct system to unconditioned spaces: gaps around filter racks, missing end caps on trunk lines, and penetrations for wiring or refrigerant lines. We pressurize the system and use a smoke pencil or theatrical fog to locate leaks that aren’t visible to inspection cameras, then seal each point with appropriate material (mastic for metal, foam sealant for larger penetrations, metal patches for corroded areas). In Leesburg townhomes with shared walls, we’ve found leaks that pressurized wall cavities and carried odors between units. The repair is documented with before-and-after pressure readings and photographs.
What happens when you call
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A real person answersNo phone trees - you reach a local pro.
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You get an upfront price rangeHonest numbers before anyone is dispatched.
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A background-checked tech heads outLicensed & insured, dispatched right away.
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You approve before work beginsNothing starts until you say go.
Brands We Service for Duct Repair & Sealing
CleanRun technicians work with the duct configurations paired with all major HVAC brands found in Leesburg homes. We’ve repaired and sealed ductwork connected to Carrier systems in hundreds of Lansdowne properties, often addressing the flexible return plenums that sag and leak at the furnace connection. For Trane installations, common in Woodlea and the villages near Route 15, we stock the proprietary corner gaskets and plenum adapters that fail at the 10-15 year mark. Lennox systems, frequently paired with smaller diameter flex duct in townhomes, require careful CFM matching when we replace runs to avoid overloading the blower motor.
We also regularly service Rheem, Goodman, York, Bryant, and Amana systems, plus heat pumps from Mitsubishi and Daikin where the ducted air handler connects to conventional trunk lines. Whether your system is original equipment or a replacement unit connected to existing ductwork, we photograph the configuration, identify the leak points, and quote the repair in writing before starting. If you have a written estimate from another contractor, bring it - Haven Standard Clause 7 provides a Free Second Opinion at no cost, with our written number next to theirs.
Before
AfterSigns You Need Duct Repair & Sealing Right Now
- Uneven temperatures from room to room. If your bedroom runs 8 degrees colder than the hallway in winter, or the upstairs never cools in July, the duct system is likely leaking or obstructed. We measure airflow at each register with a calibrated anemometer and compare to the design CFM to locate the failure point.
- Dust streaks on ceiling or wall near registers. Those dark lines are filtration soiling - air being pulled through gaps between the register boot and drywall, carrying attic dust and insulation fibers into your living space. The register itself is clean; the leak is behind it, and it worsens indoor air quality while wasting energy.
- Utility bills that rise without rate increases or usage changes. A 20 percent duct leak can increase heating and cooling costs by 15 to 20 percent, according to Department of Energy estimates. In Leesburg’s climate with significant heating and cooling loads, that translates to hundreds of dollars annually.
- Hissing or whistling from registers or ductwork. These sounds indicate high-velocity air escaping through a gap under pressure. The leak is often at a joint that has separated or a flex duct that has pulled off its collar. Left unrepaired, the turbulence accelerates corrosion and can collapse flex runs entirely.
- Musty or chemical odors when the system runs. Leaks in return ductwork can pull air from crawl spaces, garages, or wall cavities where mold, rodent activity, or stored chemicals create odor sources. The smell isn’t in your ducts - it’s being drawn into them through gaps, then distributed throughout the house.
Our Duct Repair & Sealing Process - Step by Step
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System inspection and photo documentation. We access the ductwork at the furnace, attic trunk lines, and crawl space runs, photographing every accessible section with a Rotobrush inspection camera. The images show corrosion, separation, insulation condition, and debris accumulation. You receive these photos as part of your documented job record.
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Pressure testing and leak identification. We temporarily seal the registers and pressurize the duct system with a calibrated fan, measuring total leakage and locating major leak points with a smoke pencil or infrared camera. The test provides a baseline CFM leakage figure that we compare against post-repair results.
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Written scope and price delivery. Before any repair begins, we deliver a written scope listing each repair item, the materials to be used (mastic type, insulation R-value, replacement flex diameter), and the total price. Haven Standard Clause 1 requires this; there is no “call for a quote” at CleanRun. You approve the written scope or we leave with no charge for the diagnostic.
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Repair execution with progress photography. Technicians complete the agreed repairs, photographing each sealed joint, replaced run, and insulated section. We use professional-grade equipment from Abatement Technologies and Guardsman, and mastic compound rated for the temperature range of your system. Metal repairs are fabricated on site or ordered to specification.
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Post-repair pressure test and final documentation. We repeat the pressure test to verify leakage reduction, typically targeting 10 percent or less of system airflow. The final photo record, pressure test results, and written 365-Day Done Right Promise are delivered before we leave. If the repair fails within 365 days, we return and make it right - backed in writing, not subject to manager approval.
How Much Does Duct Repair & Sealing Cost in Leesburg?
Learn how much Duct Repair & Sealing costs: for a typical single-system Leesburg home, duct sealing runs $450 to $850 depending on system accessibility and the number of joints requiring mastic application. Flex duct replacement, when a run has collapsed or torn, ranges from $180 to $340 per run including materials and insulation. Metal duct repair - cutting out corroded sections, fabricating replacements, and sealing - typically falls between $320 and $680 depending on the gauge of steel and the complexity of the fabrication. Full duct insulation replacement in an attic runs $1,200 to $2,400 for a complete system, while spot insulation repair at damaged sections starts around $220.
Several factors move these ranges. Attic access matters: a truss attic with a pull-down stair allows faster work than a crawl space requiring protective entry. The age of the ductwork affects whether we’re sealing original seams or repairing previous failed repairs layered on top of each other. System size - measured in total CFM and number of registers - determines material quantities. We quote each factor specifically in your written scope, with no per-vent pricing that hides the true total until the work is half done.
The most common overpayment we see in Leesburg is the $79 “whole house duct cleaning” coupon that becomes a $2,000 upsell once the truck is in the driveway. CleanRun does not offer teaser pricing. The written scope you approve before work starts is the price you pay. If additional issues are found during repair, we photograph them, explain the finding, and provide a supplemental written scope for your approval before continuing. No surprises, no invoice shock.
Every estimate is free, includes the full photo documentation of current conditions, and comes with no obligation. Call (571) 487-7204 to schedule.
Duct Repair & Sealing Near Leesburg - Our Service Area
CleanRun serves Leesburg and the surrounding Loudoun County corridor including Duct Repair & Sealing in Ashburn, Duct Repair & Sealing in Sterling, and extends to Herndon, South Riding, Great Falls, Reston, Chantilly, and Centreville. For homes in the northern reaches near the Potomac, we coordinate with our crews serving Germantown, Gaithersburg, and Clarksburg, Maryland. Most Leesburg appointments are scheduled within 3 to 5 business days, with diagnostic visits typically available sooner. We do not promise same-day dispatch - duct repair requires scheduled access and proper preparation - but we do answer every call with a live person who can book your estimate immediately.
Serving Leesburg, VA - Our Local Coverage Area
We’re based in the Leesburg area and also provide our Duct Repair & Sealing in Ashburn. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
Frequently Asked Questions - Duct Repair & Sealing in Leesburg
Duct repair and sealing fixes the physical pathways that distribute heated and cooled air throughout your home, closing leaks that waste energy and degrade air quality. The work includes sealing joints with mastic compound, replacing damaged flex or metal duct sections, insulating exposed runs, and pressure-testing to verify results. CleanRun delivers a written scope and price before starting, photographs every duct run before and after, and backs the work with the 365-Day Done Right Promise.
Most residential duct sealing projects in Leesburg take 4 to 6 hours for a single system, while extensive repairs involving multiple flex duct replacements or metal fabrication may extend to a full day. We schedule the work with a specific arrival window, not a vague “morning or afternoon” block, and the written scope includes the estimated duration so you can plan accordingly. Call (571) 487-7204 for an exact timeline based on your system configuration - estimates are free.
Typical duct sealing runs $450 to $850, flex duct replacement $180 to $340 per run, metal repair $320 to $680, and full insulation replacement $1,200 to $2,400 depending on system size and accessibility. CleanRun quotes every job in writing before work begins under Haven Standard Clause 1, with no per-vent pricing or post-arrival upselling. Bring a competitor’s written estimate for a Free Second Opinion under Haven Standard Clause 7.
Yes. We repair and seal ductwork connected to all major HVAC brands including systems with Aprilaire air cleaners and humidifiers, where the bypass duct or dedicated return path often leaks at the plenum connection. Our crews carry the adapters and gaskets common to these configurations, and we photograph the integration points to ensure the accessory equipment operates at designed efficiency after the repair. Whether your system includes Aprilaire, Abatement Technologies components, or any other make, we can assess and quote the repair.
We do not classify duct repair as an emergency service - a leaking duct wastes energy and degrades comfort but does not present immediate safety hazards like gas leaks or electrical failures. For complete duct separation that has disabled your system, we prioritize scheduling within 24 to 48 hours. All calls are answered by a live person, 24/7, who can assess urgency and book the earliest available diagnostic. For true HVAC emergencies (refrigerant leaks, electrical failures, gas odors), we recommend contacting your heating and cooling contractor directly.
Every duct repair and sealing job is backed by the 365-Day Done Right Promise: if the repair fails, leaks, or does not perform as scoped within one year, CleanRun returns and corrects it at no charge. This is a written guarantee delivered with your job record, not a policy subject to manager discretion. Haven Standard Clause 5: Accountable Work requires this documentation on every job. The guarantee covers our workmanship and materials; manufacturer warranties on equipment we install run separately.
Clear access to the furnace or air handler, attic pull-down stairs, and any crawl space entry points. Remove stored items within 3 feet of the work areas. We bring drop cloths, shoe covers, and containment materials, but valuable items near access points should be moved beforehand. Pets should be secured away from work areas, as attic and crawl space access requires open doors. You’ll receive a confirmation call the day before with the technician’s name and arrival window under Haven Standard Clause 3: Verified Crews. Call (571) 487-7204 to book your free estimate.
Schedule Your Duct Repair & Sealing Service in Leesburg Today
Call (571) 487-7204 to speak with a live person and schedule your free estimate. You’ll receive a written price before any work starts, a documented photo record of every duct run, and the 365-Day Done Right Promise in writing. CleanRun Air Duct Cleaning Leesburg has operated under the Haven Standard since 2013, serving over 52,000 homes with no exceptions to our pricing protocol. Bring a competitor’s written estimate for a Free Second Opinion - we’ll put our number next to it, in writing, and let the documentation speak.
Written by Tomas Reyes, Owner at CleanRun Air Duct Cleaning Leesburg, serving Leesburg, Ashburn, Duct Repair & Sealing in Sterling, and Loudoun County since 2013.