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
AfterNikro Duct Sealing & Repair: The Los Angeles Owner’s Guide
We stock and install Nikro-compatible duct sealing and repair parts for homes across Los Angeles, with most seal-and-repair jobs running between $450 and $950 installed depending on how much of the system is leaking. Most owners discover a failed seal the way you’d expect: a room that never quite cools in August, dust returning a week after cleaning, or a whistle behind a register when the blower kicks on. That’s the seal giving up. We carry the parts and do the work in one visit, and we tell you the price before anything gets touched.
Which Nikro Models This Applies To
Nikro’s negative-air machines and duct sealing equipment span several series lines, and the sealing and repair components differ across them. If your machine is a Nikro NAK series negative-air unit or a Nikro duct sealing accessory rig, the gaskets, seal fittings, and sealing wands generally interchange within the same series, but not across a 115V versus 230V motor configuration. The way to identify the right part is to check the machine’s serial plate and note the voltage and CFM rating. Then measure the sealing collar diameter; Nikro uses both 8-inch and 10-inch collars, and a mismatch means the sealing head will not hold a continuous seal around the duct opening. We keep OEM Nikro seals on hand where the original part is still in production. Where production has ended, we use quality aftermarket equivalents that meet the same tolerances. If you tell us the serial number when you call, we can usually confirm the correct fit before we show up.
Signs Your Nikro Duct Sealing & Repair Is Failing
- Visible mastic cracking or peeling at duct joints. Los Angeles heat cycles and dry air make mastic brittle over time. Once it cracks, the air you’ve paid to condition escapes into an attic or crawl space.
- Rooms that never reach the thermostat setpoint. A failing seal means the system delivers less air at the register. The thermostat keeps calling for cooling, the bill climbs, and the back bedroom stays warm.
- Dust accumulating around register grilles. When supply ducts leak, they draw attic or crawl space dust into the airflow. That dust lands on the register face first.
- A soft whistle near ducts when the blower runs. Air moving through a failing seal under pressure makes noise. It’s usually faint, but it’s there if you listen at the right joint.
- Condensation or dampness around duct connections. In Los Angeles, this is more common in crawl spaces than attics. A compromised seal lets conditioned air meet warmer air at the joint, and moisture forms.
Replacement Cost & What’s Included
For Los Angeles homes, typical Nikro-specific duct sealing and repair runs between $450 and $950 installed. At the low end, you’re looking at sealing a handful of accessible joints with mastic. At the high end, you’re replacing failed flex duct runs or re-sealing a return plenum that has pulled apart. The cost is driven by how many linear feet of duct are leaking, how much of it sits in an attic versus a crawl space, and whether existing sealant has to be removed before new mastic can bond. Our written price includes the parts, the labor, the sealing material, and a system check after the repair. We do not quote a low number and then find ‘extra problems’ once we’re inside. The price you sign off on is the price you pay, and every repair we make is covered by the 365-Day Done Right Promise. If the seal fails within a year, Roy Castellanos and our crew come back and make it right at no charge.
| Repair Scope | Typical Los Angeles Price |
|---|---|
| Seal 4-6 accessible duct joints with mastic | $450 – $600 |
| Reseal plenum plus 6-8 joints, minor collar repair | $600 – $750 |
| Replace failing flex runs and reseal full return | $750 – $950 |
DIY or Call Us?
You can safely do a visual inspection around your registers and visible duct runs. Look for cracked mastic, separated collars, or flex duct that has sagged and pulled loose. But here’s the honest part: resealing ducts properly means working with mastic while the system is off, often in an attic that hits 130 degrees in a Los Angeles summer, and doing it in a way that holds pressure. A bad patch job leaks again within months and you’ve baked for nothing. If the ductwork is damaged or the seal has failed in multiple places, skip the climb. Call us at (361) 326-5060 and we’ll handle it in one visit.
FAQs
A properly applied mastic seal on interior ductwork typically lasts 10 to 15 years. Attic ductwork in Los Angeles sees higher temperature swings, and we tell customers to expect 8 to 12 years before some resealing is needed. If you’d like us to look at what you’ve got, call (361) 326-5060 and we’ll give you an assessment in plain terms.
Yes, and in most Los Angeles homes, a repair is the right call. If the duct body is intact and the seal is what failed, we remove the old mastic, prep the joint, and reseal it. Replacement only makes sense when the duct itself is damaged, crushed, or the flex liner has separated. Call us at (361) 326-5060 and we’ll tell you which one applies to your system.
Most single-system duct sealing and repair jobs in Los Angeles take three to five hours. A full re-seal with multiple failing flex runs can run into a full day. We write the time window and the price down before we start, so there’s no guesswork and no clock ticking at your expense.
We keep common Nikro seal fittings, collars, wands, and gaskets on our trucks for the NAK negative-air series and standard sealing rigs. If a specific part is not on the truck, we order it and return for the swap rather than improvising with something off-spec. The parts we use are matched to the machine, not whatever is close enough.
Written by Roy Castellanos, Owner, Hollis Air Duct Cleaning at Hollis Air Duct Cleaning, serving Los Angeles and nearby areas.