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.
Fast, Reliable Duct Repair & Sealing Across Denver
Duct repair and sealing in Denver typically costs $280-$650 for most residential jobs, with full-system mastic sealing and metal duct repair running toward the higher end. We’re CleanRun Duct Repair & Cleaning, and our Duct Repair & Sealing crews work Denver neighborhoods daily from our metro office here in the city. Call (719) 259-4520 for a written estimate before any work starts - that’s Haven Standard Clause 1, and it’s how we’ve operated since 2013.
Why CleanRun Air Duct Cleaning Parker Is Denver’s Preferred Duct Repair & Sealing Company
We’ve served more than 52,000 homes since 2013, and a significant share of those jobs have been in Denver’s inner-ring neighborhoods where the housing stock tells a consistent story. Our technicians are background-checked, uniformed, and identified by name before arrival - Haven Standard Clause 3: Verified Crews. Every job concludes with a Documented Photo Record of every duct run, delivered to you as a standard deliverable, not an upsell.
Our Denver customers return to us because we name a written price before removing a single panel, and because they can verify what was done. The 365-Day Done Right Promise is backed in writing on every job. If the work isn’t right, we make it right. No manager approval required.
Calls are answered by a live person, 24/7, and scheduling is coordinated from our Denver office. We don’t subcontract to crews who don’t know the difference between a Harvey Park crawl space and a Capitol Hill retrofit cavity.
Our Duct Repair & Sealing Services in Denver

Duct Sealing
Denver’s high-altitude, low-humidity air holds wildfire ash and brown-cloud inversion particulates in suspension far longer than lower-elevation cities, so duct runs here collect fine, flour-like dust that migrates past registers and settles in return drops. The fine fraction that mastic and proper sealing are designed to stop, not just clean. Post-Marshall Fire (Dec 2021) ash intrusions across the metro made sealing and source removal of the supply and return trunks the default fix, not a refresh of registers. We seal trunk seams, register boots, and plenum connections with mastic sealant - not tape that dries and fails - and we photograph every sealed joint before closing access.

Flex Duct Repair
Flex duct in Denver’s 1950s-70s ranch homes often runs through unconditioned crawl spaces where ground moisture and rodent activity take their toll. We replace crushed or chewed flex runs with insulated duct rated for the temperature swings these spaces see, and we seal the connection points with mechanical fasteners and mastic. In Harvey Park, our crew pulled a 1962 ranch’s original sheet-metal trunk out of a crawl space and found three crushed runs and a disconnected boot at the hall register; camera inspection showed rodent-chewed flex duct feeding a bedroom branch. We sealed the trunk seams with mastic, replaced the flex run with insulated duct, reattached the boot, and re-balanced the supply and return ducts - the air handler’s static pressure dropped back into spec and the homeowner finally got flow to the back bedroom.

Metal Duct Repair
Original sheet-metal ductwork in Denver’s older neighborhoods develops pinhole rust and disconnected joints from decades of ground moisture in crawl spaces. Sealing the register boot without sealing the trunk is a false fix - we’ve seen it repeatedly in Barnum and Westwood ranches where a previous company “sealed” the visible end while the trunk leaked 30% of conditioned air into the dirt below. We repair or replace rusted sections, re-seal all longitudinal and transverse joints with mastic, and pressure-test the system to verify integrity.

Duct Insulation
Uninsulated metal duct in Denver crawl spaces loses efficiency fast when outside air hits 20°F and the crawl space follows. We install proper insulation on repaired or replaced runs, sealed at all seams, to maintain delivered air temperature from the plenum to the register. This matters especially in Montbello and the older Aurora corridors where original systems were never designed for modern efficiency expectations.

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.
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AfterTrusted Brands We Service in Denver
Our equipment roster includes Rotobrush agitation systems, Nikro negative-pressure extractors, and Honeywell air quality components - brands customers can look up independently before agreeing to a price. We stock common repair parts for Denver-area homes, including flex duct, mastic, mechanical fasteners, and insulated boot connectors, so most jobs don’t wait on shipping. Our technicians carry Guardsman-grade sealing compounds rated for the temperature and pressure cycles of residential HVAC systems.
Common Duct Repair & Sealing Problems We See in Denver Homes

- Original 1950s-70s sheet-metal duct in uninsulated crawl spaces develops pinhole rust and disconnected joints from ground moisture and rodent intrusion. Sealing the register boot without sealing the trunk is a false fix - the real leak is underground, invisible from the living space.
- Retrofitted duct in pre-WWII Capitol Hill and Baker wall/ceiling cavities has irregular geometry that traps debris and makes camera inspection and agitation tool access difficult. Partial cleanings leave source material behind; proper repair requires accessing and sealing the original penetration points.
- High-altitude wildfire smoke and inversion events load supply and return ducts with fine ash that migrates through loose joints. Unsealed runs re-entrain that ash every time the blower motor cycles. After the December 2021 Marshall Fire blanketed the entire metro in ash for several days, demand for smoke-contamination duct cleanings spiked across the region in a way that has no parallel in any neighboring plains city.
- Disconnected or crushed flex duct runs in Harvey Park and Barnum ranches, often found during scheduled cleanings, where decades of crawl-space traffic or rodent nesting have collapsed the airway. The homeowner reports “that room never heats” - and the camera shows why.
Pricing for Duct Repair & Sealing in Denver, CO
A typical duct sealing job in Denver runs $280-$450 for a single-system home with accessible trunk lines. Flex duct repair or replacement, including insulated duct and mastic-sealed connections, ranges $180-$340 per run depending on crawl-space access and length. Metal duct repair - section replacement, rust remediation, and full trunk re-sealing - runs $420-$650 for most residential systems. Full-system mastic sealing with pressure verification starts around $520 and scales with system size and access difficulty.
What moves the number: crawl-space clearance (some Denver ranches have 18 inches or less), number of disconnected or crushed runs found, whether the plenum itself needs re-sealing, and whether we need to cut access panels in finished basement ceilings. We deliver a written price before any work starts, every time - Haven Standard Clause 1. No per-vent pricing, no teaser coupons, no invoice inflation once the van is on your drive. Bring a competitor’s written estimate; we provide a Free Second Opinion at no cost.
We Also Serve Cities Near Denver

Our Duct Repair & Sealing in Denver crews also work Aurora, Englewood, Littleton, and Lone Tree from the same Denver-coordinated dispatch. The same written-price protocol, same Documented Photo Record, same 365-Day Done Right Promise applies in every zip code we touch.
Serving Denver, CO - Our Local Coverage Area
We’re based in the Denver area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
FAQs - Duct Repair & Sealing in Denver

Sheet-metal duct in unconditioned crawl spaces rusts and disconnects from ground moisture and rodent activity while the furnace itself sits in conditioned space. The duct is the system’s weak link - and in Harvey Park and similar 1950s-70s Denver neighborhoods, it’s often original to the home and has never been professionally sealed. Call (719) 259-4520 for a written estimate - camera inspection is included.
Sealing is the priority if the ductwork has loose joints or disconnected boots, because unsealed runs will re-entrain ash every time the blower cycles. We inspect with a camera first; if the trunk is compromised, sealing and source removal of the supply and return trunks is the default fix, not just a register refresh. The Marshall Fire taught Denver homeowners this sequence the hard way. Call (719) 259-4520 to schedule.
We use a borescope camera with articulating head to navigate irregular geometry in these pre-WWII retrofits, and we access what we can from existing register openings or small, repairable access cuts. The irregular angles trap debris and limit agitation tool reach, so we map the system first and explain exactly what we can and cannot reach before naming a price. Call (719) 259-4520 for an exact scope and written quote.
Yes - during winter inversions, Denver’s documented “brown cloud” episodes trap vehicle exhaust and industrial pollutants that HVAC systems pull and recirculate through ductwork for days. We pay particular attention to return duct integrity during fall preventive work, because a leaky return in inversion season draws contaminated attic or crawl-space air into the breathing stream. Call (719) 259-4520 to schedule pre-season inspection.
The H.A.V.E.N. Standard governs every job: Clause 1 mandates written price before work starts; Clause 3 requires verified, background-checked crews; and the full standard includes the Documented Photo Record and 365-Day Done Right Promise. Our mastic application follows SMACNA sealing standards for residential static pressure, and we pressure-test sealed systems to verify. Call (719) 259-4520 with questions - estimates are free.
Written by Tomas Reyes, Owner at CleanRun Duct Repair & Cleaning, serving Denver since 2013.




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