Fast, Reliable Duct Repair & Sealing Across London
Duct repair and sealing in London, OH typically costs $180-$650 depending on whether we’re patching a single seam or resealing an entire trunk line, and most jobs are completed in one visit. If your home was built between the 1930s and 1960s - which describes most of London’s housing stock - your galvanized or bare sheet-metal ductwork has likely never been professionally sealed and is almost certainly leaking conditioned air into your attic or crawlspace.
We’re Bellows Air Duct & Vent Co., and we’ve been driving out to Madison County from our main office for more than four decades. London’s about 25 miles west of Columbus, and we make that trip regularly. Our technicians know the difference between a ranch on Elm Street and a two-story near downtown, and they know what kind of duct problems each one develops. If you’re seeing dust streaks around your registers, smelling must from the vents, or your upstairs rooms never cool down, call us at (844) 685-6342. We’ll answer the phone, day or night.
Why Bellows Air Duct & Vent Co. Is London’s Preferred Duct Repair & Sealing Company
London homeowners don’t call us for flashy trucks or coupon gimmicks. They call because their neighbor called, or because they got burned by a low-bid operator from Columbus who changed the price at the door. We’ve built our reputation in Madison County on showing one honest price before we start, then standing behind the work for 90 days with no paperwork if something needs touching up.
Our customers in London leave reviews that mention the same things: the technician showed up in a uniform, explained what he found with a camera, and the invoice matched the quote. We don’t publish star counts or review totals - we let our local reputation speak for itself. What we will say is that Ray Castillo, who has led this company since its founding in 1984, still answers to the K.E.Y.S. values code on every job, and that code hasn’t changed.
Response time to London is typically same-day or next-day during the week, and we keep our scheduling tight so we’re not leaving you waiting. Our technicians carry mastic sealant, fiberglass mesh, and insulation materials on every truck, so most London repairs don’t require a return trip.
We also understand something about London that out-of-town crews miss: this city’s older homes weren’t built for modern HVAC loads, and their ductwork reflects that. Our Duct Repair & Sealing team has handled more original galvanized trunk lines in the last five years than most Columbus-area companies see in a decade.
Our Duct Repair & Sealing Services in London
Duct Sealing with Mastic Sealant
Most London homes built before 1970 have duct joints that were originally sealed with cloth tape or nothing at all. That tape dries out and fails. We use professional-grade mastic sealant, applied with a brush and reinforced with fiberglass mesh on larger gaps. A typical mastic sealing job for a London ranch with a single trunk and branch system runs $280-$450. For a two-story with multiple zones, expect $400-$650. The sealant cures to a flexible, permanent bond that won’t degrade like tape.
Last October, on Elm Street near the south edge of town, we sealed a metal duct run in a 1950s ranch that had been sucking combine-season grain dust into the living room through a cracked return boot. The original galvanized ducts had corroded at a seam, and we applied mastic sealant and fiberglass mesh to stop the leak, then insulated the run to prevent condensation on those humid fall mornings.
Metal Duct Repair
London’s legacy galvanized ductwork develops problems you don’t see in newer flex-duct systems. Seams split after decades of thermal cycling, especially in attics where summer heat pushes metal fatigue. Corrosion forms at low points where condensation collects. We patch small holes with metal patches and mastic, rebuild damaged sections with matching gauge metal, and replace rotted return boots. Metal duct repair in London typically runs $180-$380 for spot repairs, or $450-$850 if we’re rebuilding a section of trunk line.
The challenge in London is parts availability. Manual dampers from the 1950s, vintage register boots, and certain galvanized fittings haven’t been manufactured in decades. When we can’t source an exact replacement, we fabricate or adapt modern components to fit without replacing the entire system. That’s the square deal: fix what’s broken, don’t sell you what you don’t need.
Flex Duct Repair
Some London homes have had partial retrofits where flex duct was spliced onto original metal trunk lines. The connection points are common failure spots, and flex duct itself degrades in hot attics. We replace crushed or torn flex sections, secure connections with proper straps and mastic, and ensure the new material is rated for the temperature swings in your attic. Flex duct repairs in London typically run $220-$400.
Duct Insulation
Central Ohio’s humid summers create condensation inside poorly insulated duct runs, and London’s flat, open Madison County terrain offers little wind break, allowing heavy ragweed pollen loads and field particulates to infiltrate through outdoor air intakes. Uninsulated or degraded duct insulation accelerates biofilm and dust buildup compared to more sheltered settings. We install foil-faced fiberglass insulation on metal trunk lines and replace water-damaged flex duct with properly insulated new runs. Duct insulation work in London runs $300-$600 for typical residential systems.
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.
Trusted Brands We Service in London
We carry equipment and materials from Abatement Technologies, Rotobrush, and Aprilaire - the same brands serious HVAC contractors specify for commercial jobs. For London’s older homes, this matters because we need reliable, consistent products that bond well to aged galvanized metal and perform through Ohio’s temperature swings. We stock mastic sealant, fiberglass mesh, and insulation materials locally, so we’re not waiting on shipments when your system is leaking. Most London repairs are completed in a single visit because our trucks are loaded for the specific challenges these legacy systems present.
Common Duct Repair & Sealing Problems We See in London Homes
- Failed galvanized seams in attics. Original duct seams in London’s postwar ranches were locked or spot-welded, not sealed. After 60-70 years of expansion and contraction, these seams open up and draw 130-degree attic air into your system in summer. We find this on almost every 1950s ranch we inspect in the 43140 area.
- Negative pressure pulling agricultural debris through crawlspaces. Undersized return ducts in London’s older homes create suction that pulls field particulates through unsealed floor joist gaps. During fall harvest, when corn and soybean chaff is airborne across Madison County, this contamination peaks. Homes on the south and west edges of London, where subdivisions border active cropland, see the worst of it.
- Corroded return boots and plenums. The sheet-metal box where your return duct meets the air handler collects condensation and debris, accelerating rust. In London’s 1930s-1960s housing stock, these boots were often fabricated on-site from bare galvanized metal with no protective coating. Replacement requires custom fabrication when original sizes are unavailable.
- Damaged insulation from rodent activity or water saturation. Older duct insulation degrades and compresses, losing its R-value. In London’s humid climate, once insulation gets wet, it stays wet and becomes a mold substrate. We remove saturated insulation, repair the underlying duct, and install new, properly sealed insulation that won’t trap moisture.
Pricing for Duct Repair & Sealing in London, OH
Here’s what duct repair and sealing costs in London’s market:
- Spot mastic sealing (single leak or joint): $180-$280
- Full mastic sealing of trunk and branch system: $280-$650
- Metal duct patch or small section rebuild: $180-$380
- Trunk line section replacement (custom fabricated): $450-$850
- Flex duct repair or replacement: $220-$400
- Duct insulation replacement: $300-$600
- Return boot or plenum rebuild: $320-$580
What moves you up or down within these ranges: accessibility (crawlspace vs. basement), extent of corrosion damage, whether we need to fabricate custom fittings for obsolete sizes, and whether insulation replacement is bundled with sealing work. We inspect with a camera before quoting, so you see what we see. No price changes at the door. We also honor our standing offers: $50 off any repair over $250, and a free second opinion on any written estimate you’ve already received.
Call (844) 685-6342 for a free estimate - we’ll show you exactly what needs fixing and what it costs before any work begins.
We Also Serve Cities Near London
Our service area extends throughout Madison County and into western Franklin County. We regularly drive to Lincoln Village, Hilliard, Grove City, and Springfield for duct repair and sealing calls. If you’re in any of these communities and dealing with legacy ductwork, aging metal seams, or harvest-season contamination, we cover you too. Our London customers often refer neighbors in these towns, and we make those trips with the same equipment and the same upfront pricing.
Serving London, OH - Our Local Coverage Area
We’re based in the London 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 London
Yes, in most cases we can patch or seal a leaky seam without replacing the entire trunk line. We clean the area, apply fiberglass mesh over the gap, then brush on two coats of mastic sealant that cures to a permanent, flexible bond. For larger splits or corroded sections, we may need to cut in a custom-fabricated metal patch. Call (844) 685-6342 and we’ll camera-inspect the damage to give you an exact quote - estimates are free.
Yes, late September through October is the critical window for duct inspection in your area. Technicians working London’s south and west edges regularly pull combine-season chaff and silage dust out of return-air plenums every October. If your ducts have any leaks, that’s when agricultural debris infiltration peaks. We recommend sealing before harvest starts, not after. Call us in early September to get ahead of it.
We can often free stuck dampers, but replacement is frequently necessary because vintage damper hardware is no longer manufactured. When we can’t source an exact match, we adapt modern dampers to fit your existing ductwork. This is a common issue in London’s in-town two-stories. The repair typically runs $180-$320 per damper location. We’ll show you the condition with our camera before recommending replacement.
We use water-based mastic sealant rated for HVAC applications, reinforced with fiberglass mesh on gaps larger than 1/8 inch. This is the industry standard for permanent metal duct sealing, and it outperforms foil tape or duct tape by decades. For London’s older galvanized systems, we select mastic formulated for adhesion to aged metal surfaces. The material is non-toxic when cured and carries no odor.
Light through duct joints indicates significant air leakage, which is an efficiency and air-quality problem rather than an immediate fire hazard in most cases. However, if your furnace is gas-fired and leaking return air is drawing combustion byproducts into the living space, that becomes a safety concern. We treat all crawlspace duct leaks as priority repairs because they pull in whatever is in that crawlspace - moisture, mold spores, and in London’s agricultural areas, field particulates. Call (844) 685-6342 and we’ll inspect it promptly.
Written by Ray Castillo, Owner at Bellows Air Duct & Vent Co., serving London since 1984.