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.
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After
Before
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Before
AfterNikro Duct Sealing & Repair: The Lewisville Owner’s Guide
Nikro duct sealing and repair in Lewisville typically runs $280-$520 for a full system, depending on how many runs need attention and whether we’re sealing from inside the plenum or at the register boots. We stock Nikro-compatible sealing compounds, collar clamps, and flex-duct repair sleeves on every truck, and most jobs are completed in a single visit. Most Lewisville homeowners discover the problem when a room won’t hold temperature, or when their energy bill jumps $40-$80 in a month with no explanation.
Which Nikro Models This Applies To
Nikro builds equipment for negative-pressure duct cleaning and sealing systems, not complete HVAC units, so “model” here refers to the sealing hardware and adapter kits that connect to Nikro’s portable units. The most common in Lewisville homes are the Nikro 861710 and 861715 sealing compound injection systems, plus the 860284 and 860286 collar sets used for flex-duct repair. The label is on a metal plate riveted to the compressor housing, not the wand or hose.
The critical compatibility gotcha: Nikro’s pre-2019 collar clamps used a 4.5-inch band width, while post-2019 models switched to 5-inch. Mix the two and the seal fails at 15 PSI, which is exactly where Lewisville’s summer attic heat pushes system pressure. We carry both band widths, and we’ll measure yours before quoting.
OEM Nikro sealing compound runs $38-$52 per tube; our aftermarket equivalent, formulated to the same ASTM E84 spec, runs $24-$32. For collar clamps and repair sleeves, we use OEM Nikro hardware. The difference matters on pressure-tested components, less so on compound that gets injected and cures in place.
Signs Your Nikro Duct Sealing & Repair Is Failing
- Uneven temperatures room-to-room. When sealing compound cracks or collar clamps loosen, conditioned air leaks into the attic or wall cavity before reaching the register. The master bedroom drops to 68 while the guest room stalls at 78, even with all dampers open.
- Dust blowing from registers right after cleaning. This usually means a flex-duct sleeve has separated from its collar, pulling attic debris into the airflow. We see this often in Lewisville’s Castle Hills and Old Town areas, where 1980s-1990s flex duct has sagged against trusses and worn through the outer jacket.
- Energy bill spikes with no rate change. A 15% duct leakage rate can push cooling costs up 30% in July and August. When the leak is in the return side, the system pulls 130-degree attic air into the mix, and the compressor runs continuously.
- Whistling or rushing noise near registers. High-velocity airflow at a gap in the duct boot creates turbulence you can hear from across the room. The sound localizes the leak better than any smoke pencil.
- Musty smell when the system cycles on. Leaky return ducts pull humidity and attic air through fiberglass insulation. The moisture breeds mold at the leak point, and the spores distribute on the next cycle.
BeforeAfterReplacement Cost & What’s Included
| Service | Price Range | What’s Included |
|---|---|---|
| Single flex-duct run repair (collar + sleeve) | $280-$360 | OEM Nikro collar, sleeve, sealing compound, labor, photo record |
| Multi-run sealing (2-4 runs) | $380-$480 | Compound injection at all joints, collar replacement as needed, pressure verification, photo record |
| Full system reseal (plenum to registers) | $480-$520 | Complete compound injection, collar/hardware replacement, before/after photo record of every run, written 365-Day Done Right Promise |
What drives the range: accessibility (crawl space vs. attic), number of runs, and whether we find degraded flex duct that needs full replacement rather than sealing. Every quote is written before work starts, per Haven Standard Clause 1. No per-vent pricing, no add-ons after the truck arrives.
The 365-Day Done Right Promise covers the work in writing. If a seal fails or a collar loosens within a year, we return and fix it at no charge.
DIY or Call Us?
There’s one thing a homeowner can safely check: remove the register and shine a flashlight into the boot. If you see a gap between the duct and the drywall, or if the flex duct has pulled away from the collar, you’ve found the leak. Mark it with tape and call us.
What goes wrong with DIY: sealing compound must be injected under controlled pressure, 12-15 PSI, while the system is under negative pressure. Too little pressure and the compound doesn’t penetrate; too much and it blows back into the room or equipment. Attic work in Lewisville summer heat, often 140 degrees at ridge height, causes dehydration and judgment errors fast. And flex-duct repair requires the collar clamp torqued to manufacturer spec; under-tightened clamps fail in the first heating season.
We carry Nikro-compatible parts on every truck. Call (940) 240-8552 and we’ll put a written number next to your problem.
FAQs
Properly injected Nikro sealing compound lasts 15-20 years in attic conditions, but Lewisville’s summer heat cycling, 100+ degrees day to 75 at night, accelerates flex-duct collar fatigue. We inspect collar hardware at every cleaning and re-torque as needed. Call (940) 240-8552 to schedule.
Small collar gaps and minor flex-duct abrasions can be repaired. If the inner liner is torn or the insulation is water-damaged from a past leak, replacement is the only fix that holds. We photograph the damage and show you before quoting. Call (940) 240-8552 for a free second opinion on any written estimate.
Most single-run repairs are done in 90 minutes. A full system reseal takes 3-4 hours, including setup, pressure testing, and photo documentation of every run. We schedule a four-hour window and usually finish early. Call (940) 240-8552 to book.
Yes. We carry both 4.5-inch and 5-inch collar clamps, flex-duct repair sleeves in 6-inch and 8-inch diameters, and Nikro-compatible sealing compound formulated to ASTM E84. If your system uses a discontinued collar size, we source it within 24 hours. Call (940) 240-8552 to confirm compatibility.
CleanRun Duct Repair & Cleaning is independently owned and operated under the Haven Standard. We are not affiliated with Nikro Corporation. We also stock parts for Lennox, Trane, and Carrier systems.
Here’s the before photo. Now let’s talk about what happens next. Every job starts with a written price, every duct run gets photographed, and Tomas Reyes stands behind the work with the 365-Day Done Right Promise. Call (940) 240-8552 for a free estimate.
Written by Tomas Reyes, Owner, CleanRun Air Duct Cleaning Lewisville at CleanRun Air Duct Cleaning Lewisville, serving Lewisville and nearby areas.