Aprilaire Duct Sealing Nationwide

Aprilaire Duct Sealing in Los Angeles: What to Know First

Aprilaire duct sealing in Los Angeles typically runs between $450 and $1,100 for a whole-system job, depending on duct accessibility and how much leakage the system has. We’re an independent Aprilaire service provider, not a factory-authorized shop, which means we can use whichever sealing mastic and tape actually holds on your specific ductwork without a corporate parts catalog dictating the job. Most Aprilaire sealing work we handle is done in a single visit of four to six hours.

Call (361) 326-5060

This page is for homeowners in Los Angeles who own Aprilaire equipment, suspect their ducts are leaking, and want a straight answer on what it costs and what the fix involves. Every job gets a written price before we touch anything. Call (361) 326-5060 and we’ll talk through it.

• Typical cost: $450-$1,100 whole-system, written before work starts
• Typical timeline: One visit, four to six hours on a standard Los Angeles home
• Warranty posture: 365-Day Done Right Promise in writing
• Parts approach: Aprilaire-compatible mastic, tapes, and collars chosen for your duct material, not a factory mandate

How Aprilaire Products Fail – and How We Fix Them

Aprilaire makes solid equipment. But most of the Aprilaire jobs we see in Los Angeles aren’t about the machine failing. They’re about the ductwork connected to it leaking, and that leakage compounds the further it gets from the unit. Here’s what we actually find when we open up an Aprilaire system’s ductwork in LA homes.

• Aprilaire 5000-series electronic air cleaner connected to leaky return ducts. This is the single most common Aprilaire-related leak scenario we see in Los Angeles. The Aprilaire 5000 is a high-resistance filter, and when it’s installed on a return with small leaks, those leaks become louder and pull harder. Symptoms: a whistling sound near the filter cabinet, dust streaks on the return grille, and the filter looking dirty far sooner than it should. We seal the return plenum and the first few feet of return duct, then verify static pressure drops to normal. No new filter needed, no unit replacement.
• Aprilaire 700 and 800 series steam humidifiers with duct collars that sag. Los Angeles homes with central heat see these units on the supply plenum. The sheet-metal collar that connects the humidifier to the duct is frequently undersized or installed without enough screws. After a few LA seasons of heating and cooling cycles, that collar sags, the bypass pipe loosens, and conditioned air leaks into the attic or crawlspace. We pull the collar, apply a continuous bead of duct mastic, remount with proper fasteners, and re-seal the bypass connection. This is usually a $150-$250 fix when caught early, versus a much bigger repair if the sag lets moisture into the duct insulation.
• Aprilaire 8100 energy recovery ventilator (ERV) with unbalanced fresh-air ducting. Homes in Los Angeles near the coast, in neighborhoods like Playa del Rey or Mar Vista, use these to bring in fresh air without losing all the cooling. The problem is that the fresh-air and exhaust ducts on an Aprilaire 8100 are often installed with short radius elbows and gaps at the roof or wall penetration. We seal those gaps, and more importantly, we check the balancing dampers and verify the two airstreams are moving at the intended rates. A leaky ERV duct isn’t just losing air; it’s pulling attic air into the fresh-air intake.
• Aprilaire 2210 and 3210 media filter cabinets with torn gaskets at the access door. These filter cabinets sit between the return duct and the furnace or air handler. The gasket on the filter access door is a foam strip that dries out in LA’s low-humidity inland areas like the San Fernando Valley. Once it cracks, the cabinet door leaks unconditioned attic air directly into the system. We replace the gasket with a closed-cell foam that holds up better in dry heat, and we re-seal the cabinet-to-duct joints with mastic. It’s a small job, often under $200, but it dramatically improves pressure balance.
• Aprilaire 600 series humidifier installed on the wrong side of a leaky duct section. Sometimes we arrive at a Los Angeles home and the Aprilaire humidifier is working correctly, but it’s mounted on an old duct run that was never sealed. That means humidified air is escaping into the attic before it ever reaches the living space. We seal the entire supply run from the plenum to the first branch takeoff. The humidifier stays. The leak disappears. And the homeowner finally gets the humidity level the Aprilaire unit was supposed to deliver.

Our Aprilaire Duct Sealing Process

Here’s how a typical Aprilaire duct sealing job goes, from the first call to the final walkthrough. No mystery steps. No surprises in the invoice.

1. 1
   Phone call and system notes. You call (361) 326-5060. We ask what Aprilaire equipment you have, where it’s located, and what made you think the ducts are leaking. We give you a general range on the call, not a hard number. Then we schedule a visit inside a specific window.
2. 2
   In-home inspection and static pressure reading. Our technician arrives, uniformed and background-checked. We check the Aprilaire unit, the filter, the plenums, and accessible duct runs. We take a static pressure reading to quantify how much restriction and leakage is present. Then we write down a firm price. That number does not move.
3. 3
   Parts decision: OEM versus quality aftermarket. For Aprilaire-specific components like filter cabinet gaskets or bypass collars, we use Aprilaire-compatible parts when the fit matters. For generic sealing materials like water-based duct mastic, UL-listed foil tape, and duct sealant, we use commercial-grade product that meets SMACNA standards. We’ll tell you which is which and why.
4. 4
   The sealing work itself. We seal every accessible joint: plenum connections, branch takeoffs, filter cabinet seams, register boots, and the first few feet of return duct. We use mastic on permanent connections and foil tape where a removable seam needs to stay serviceable. We don’t paint mastic over moving parts or access panels.
5. 5
   Post-seal pressure test and airflow check. After sealing, we re-check static pressure and confirm airflow at a sample of registers. You should notice the difference immediately: less noise, steadier temperature, and a system that cycles less often.
6. 6
   Cleanup and the 365-Day Done Right Promise. We leave the site the way The Garrison Standard demands: clean, no debris, no leftover materials. Then we write down what we did, what we used, and what the guarantee covers. If the seal fails within a year, we return at no charge. That’s not a verbal promise; it’s printed on the invoice.

What Aprilaire Duct Sealing Costs in Los Angeles

Here are the price ranges we quote most often for Aprilaire duct sealing work in Los Angeles. These are whole-job figures, not per-vent pricing.

• Single filter cabinet gasket replacement and seal: $120-$220
• Supply plenum and takeoff sealing (one system): $350-$550
• Whole-home duct sealing, accessible attic or crawlspace: $650-$1,100
• ERV or humidifier duct collar repair and seal: $150-$350
• Return duct section replacement and seal: $300-$600 depending on length

What moves the price is duct accessibility: a tight crawlspace in an older Eagle Rock or Highland Park home takes longer than a standing attic in a newer Westside build. The number of plenums, the age of the duct material, and whether we need to remove a section of failed duct rather than just re-seal it all factor in. You’ll get the exact number in writing before any work begins. Call (361) 326-5060 for a free estimate.

Why Los Angeles Homeowners Call Hollis Air Duct Cleaning for Aprilaire Work

We’ve been at this since 2004, and we’ve built the company around a simple discipline: show up inside the window, price it in writing, do it by the book, and leave the site clean. That’s The Garrison Code, and it applies whether we’re sealing an Aprilaire filter cabinet or running a negative-air cleaning on a whole home in Sherman Oaks.

Roy Castellanos grew up in Boyle Heights and trained in the mechanical trades through the sheet metal and air conditioning program at Los Angeles Trade-Technical College. He’s spent years working on duct systems across Los Angeles County before starting Hollis Air Duct Cleaning. When a technician walks into your home, they carry that same standard. We work on Aprilaire weekly. We also service Lennox, Trane, and Carrier systems, which means we’re not brand-locked into calling an Aprilaire dealer for a part. We know what crosses over and what doesn’t.

Every job is covered by a written 365-Day Done Right Promise. If the seal fails within a year, we return and make it right at no charge. That includes a free second visit. Clean ducts, straight answers – that’s the whole job.

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