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.
Lennox Air Duct Cleaning in San Francisco, CA | Morton’s Air Duct Cleaning
Lennox air duct cleaning in San Francisco typically costs $450 to $1,100 for a full-system clean, depending on home size and how many returns feed the system. We’re Morton’s Air Duct Cleaning, an independent Lennox service provider in our San Francisco service area since 2005. What makes our Lennox work different here is simple: most San Francisco homes that have Lennox equipment got it as a retrofit into Victorian or Edwardian framing that was never built for ductwork. That changes how the system breathes, how debris collects, and what a proper cleaning actually requires. Call us at (323) 918-4345 for a written estimate before any work starts.
Why San Francisco Residents Choose Us for Lennox Service
We’ve worked on Lennox residential systems across San Francisco long enough to know what happens when a communicating SLP98 gets tied into a century-old return path. Paul Adeyemi, our owner, grew up in Inglewood and learned ventilation mechanics hands-on at Los Angeles Trade-Technical College before spending the better part of two decades inside the walls of homes across the LA basin. That background matters here because San Francisco retrofits throw unusual problems at standard equipment. We’re an independent provider, not affiliated with or authorized by Lennox, which means we recommend what the system actually needs rather than what a manufacturer program tells us to sell. Whether it’s a G-series furnace in a Richmond stucco home or a variable-speed Elite in a Noe Valley flat, our technicians know the equipment, the parts, and the local ductwork realities. We use Lennox sales & service knowledge built from years of field work, not a training manual.
Common Lennox Air Duct Cleaning Problems We Solve in San Francisco
- Return duct leakage on upflow furnaces in tight Victorian closets. Lennox upflow units installed in San Francisco’s narrow Victorian closets often have return ducts pulled through framing cavities never sealed properly. The blower draws attic air, crawlspace dust, and plaster particles into the cabinet, loading the blower wheel with debris that cuts airflow and shortens motor life.
- High static pressure from undersized retrofit returns. Row houses in the Mission and Outer Sunset usually got ducted systems as afterthoughts. Sharp bends and narrow returns feeding a Lennox air handler drive static pressure up, strain the blower motor, and pull debris into the coil face faster than a purpose-built duct run ever would.
- Coil fouling and microbial growth in fog-damp homes. Lennox cased coils in the Outer Sunset and Richmond sit in homes where the marine layer keeps indoor humidity unusually high. Fog-borne moisture combines with construction dust from near-constant remodeling to coat the evaporator face, and in damp conditions that coating supports mold and mildew growth even when the air conditioner hardly runs.
- Heat exchanger corrosion on older Lennox furnaces. G-series and early Merit models in San Francisco homes often vent through flues retrofitted decades ago. Years of dust drawn through floor-grate stubs and return runs accelerates corrosion on the heat exchanger, and a cracked exchanger is a carbon monoxide risk that needs professional inspection.
- Filter drawer leaks pulling debris from below-floor cavities. Lennox filter drawers on retrofit installations in San Francisco frequently sit above old floor-furnace cavities. If the drawer frame isn’t sealed, the blower pulls damp, debris-laden air from below the floor, coating the filter faster and sending that air through the coil and into the house.
Lennox Service in San Francisco: What Local Conditions Mean for Your Equipment
Here’s something specific to San Francisco that doesn’t show up in a Lennox manual. In the Inner Sunset and Cole Valley, many Victorians still have their original floor-furnace grates and short stub duct runs beneath finished floors. When a Lennox central system was retrofitted, those grilles and stubs were often left in place and tied into the new return path rather than removed. The marine layer keeps those below-floor cavities damp all year, and the debris trapped inside them, compacted pet dander, fog-borne particulates, remodel dust, can support mold growth even when the Lennox system only runs intermittently. We’ve pulled grilles in Cole Valley that hadn’t been opened since the gas floor furnace was converted decades ago. The air your Lennox blower pulls through those cavities carries whatever lives in them. That’s why our full-system cleaning includes inspecting and cleaning below-floor return stubs whenever a home has them, not just the main duct runs.
A recent job in an Inner Sunset Victorian flat off Judah Street shows how this plays out. The home had a Lennox SL280 with a return tied into an old floor-furnace stub. The grille was packed with compacted pet dander and remodel dust, and the flexible return run had pulled apart at a sharp bend, sending attic air into the blower. We sealed the return with mastic, replaced the damaged flex section, cleaned the blower wheel and cased coil, and the homeowner reported both better airflow and far less musty odor. That kind of repair-plus-cleaning work is routine in San Francisco and rare in cities with purpose-built forced-air systems.
Lennox Models & Products We Service in San Francisco
We service the Lennox lines most common in San Francisco homes. That includes Merit Series gas furnaces like the ML180 and ML193, Elite Series furnaces and air handlers including the EL180 and EL296, and Dave Lennox Signature Collection equipment such as the SL280 and SLP98 with communicating thermostats. We also work on Lennox outdoor units from 14 SEER and up, including the 14ACX and XC21, matched to indoor coils and ducted air handlers. For critical components such as control boards, igniters, blower motors, and heat exchangers, we use Lennox OEM parts. For filters, flex duct, mastic, and standard fittings, we use quality aftermarket equivalents where the spec matches. For older Lennox equipment, we give you an honest repair-versus-replace assessment based on heat exchanger condition, parts availability, and system efficiency rather than pushing a sale.
Lennox Service Pricing in San Francisco
Air Duct Cleaning - San Francisco for full Lennox systems runs $450 to $750 for a typical single-zone row house or flat with 8 to 12 supply vents. Larger homes or multi-system properties typically fall between $750 and $1,100. Duct sealing adds $300 to $600 depending on how many returns and plenum connections need attention. Factors that drive cost here include access: many San Francisco systems sit in crawlspaces, attics, or tight Victorian closets that take longer to work in safely, and below-floor return stubs require extra care. Every estimate is a written price before any work starts, so you know exactly what the job costs before we touch anything. Call (323) 918-4345 for a free estimate.
Serving San Francisco, CA - Our Local Coverage Area
We’re based in the San Francisco 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 - Lennox Air Duct Cleaning in San Francisco
Musty odor in a San Francisco Lennox system almost always means microbial growth is sitting somewhere in the return path or on the coil face. The marine layer keeps below-floor cavities and crawlspaces damp year-round, and when a Lennox air handler pulls air through retrofit floor stubs or unsealed return runs in a Victorian, it carries that damp, debris-laden air across the coil and into the house. The fix is cleaning the coil, blower wheel, and full return path, then sealing the leaks that let damp crawlspace air in. Call (323) 918-4345 and we’ll inspect the return path before recommending anything.
Yes. Those below-floor grates and stub duct runs are part of your return path, and they can be cleaned and sealed. In Cole Valley and the Inner Sunset, we regularly open original floor grates that haven’t been touched since the furnace was converted from a gas floor unit, clear out the compacted pet dander and construction dust, and check whether the stub run is still sealed to the main return. If it’s pulling damp cavity air, we seal it with mastic and replace any damaged flex connections. This is part of our Dryer Vent Cleaning in San Francisco full-system service, not an add-on you have to ask about.
There’s no single filter Lennox requires for every San Francisco install. What matters is the filter’s MERV rating relative to your system’s static pressure, the correct filter size for the drawer, and more than anything, changing it often enough. In fog-heavy neighborhoods like the Outer Sunset, filters load faster because indoor humidity causes more dust to stick rather than pass through. We recommend a MERV 8 to 11 filter for most Lennox systems in San Francisco, changed every 60 to 90 days, with the drawer frame checked for leaks during cleaning. Give us a call at (323) 918-4345 if the filter drawer doesn’t seal properly, that gap is pulling unfiltered crawlspace air into the blower.
Retrofit ductwork in San Francisco row houses typically leaks at connection points, floor-stub tie-ins, and sharp bends where flex duct gets crushed. Those leaks do two things: they pull attic or crawlspace air, dust, and moisture into the return stream, and they reduce airflow to the supply vents. Sealing the return path with mastic and replacing damaged flex sections restores proper airflow to the Lennox air handler, reduces blower motor strain, and prevents damp cavity air from being drawn across the coil. In foggy districts like the Richmond, sealing alone often resolves persistent musty smells. Call (323) 918-4345 and we’ll include a leak assessment with your cleaning estimate.
Yes, we inspect and clean the blower assembly and accessible heat exchanger surfaces on older Lennox furnaces, including G-series and early Merit models. We also check for cracks, corrosion, and flue concerns, and if a heat exchanger is compromised, we’ll tell you plainly and recommend a licensed HVAC technician for repair or replacement. The heat exchanger is a safety component, and a cracked exchanger can leak carbon monoxide, so that is never a cleaning-only conversation. Call (323) 918-4345 for an inspection and cleaning estimate.
Service Areas Near San Francisco
Most of our San Francisco work happens right here in the city: the Inner Sunset, Cole Valley, the Richmond, Noe Valley, and the Outer Sunset. If you’re comparing providers in other regions, we also maintain Lennox service in Seattle and Lennox service in Nashville-Davidson. Each location works to the same Cedarwell Care Promise, but nobody outside a city built on Victorian framing and fog really understands retrofit ductwork the way our local crews do.
Book Your Lennox Service in San Francisco Today
Call (323) 918-4345 and a live person answers, day or night. We’ll schedule a walkthrough, give you a written price before any work starts, and show you photos of the clean-up before the crew leaves. Before we start, let me show you exactly what we found and exactly what it will cost to fix it.
Written by Paul Adeyemi, Owner at Morton’s Air Duct Cleaning, serving San Francisco since 2005.




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