Whole-home duct cleaning
Dryer vent cleaning
Camera inspection
Sanitizing & deodorizingWhole-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 Foster City, CA
We provide independent Lennox air duct cleaning across Foster City, and the work here looks different than it does five miles inland. Most Foster City homes sit on engineered fill in former marshland, which means Lennox return boots and plenums collect fine gray lagoon silt and corrosion residue that San Mateo tract homes never see. We’re not authorized by Lennox, and we say that plainly. We are a local shop that knows how Lennox equipment behaves in this specific bay microclimate. Call (855) 382-9257 for a free estimate.

Why Foster City Residents Choose Us for Lennox Service
We’ve spent years working on Lennox furnaces and air handlers in Foster City’s planned-community tract homes, and that changes how we approach a cleaning job. Frank Peralta, our owner, studied HVAC systems at Chabot College in Hayward and worked residential and light commercial ventilation across the East Bay before starting Duct Cleaning Castro Valley in 2012. He runs a job the same way he talks about it: methodical, step-by-step, with a camera in the duct before and after so you can see exactly what changed. When you book a cleaning here, you get a written estimate, a clear scope of work, and a technician who treats Foster City’s moisture-heavy duct systems as a specific problem, not a generic one.
We name the equipment we use because it matters. Rotobrush rotary brush systems dislodge debris that a shop vac can’t reach. Nikro HEPA-rated extraction captures loosened particulates instead of recirculating them into your living room. Abatement Technologies negative-pressure containment keeps whatever we knock loose inside the ductwork and out of your air. Clean ducts are the start. Sealed, intact ducts are the finish. We do both, which matters in Foster City where bay-air moisture and torn flex go hand in hand.
Styles & brands we work with
- Whole-home duct cleaning
- Dryer vent cleaning
- Camera inspection
- Sanitizing & deodorizing
Common Lennox Air Duct Cleaning Problems We Solve in Foster City
- Gray silt and corrosion residue in Lennox return boots. Lagoon-side Foster City homes collect fine fill dust that gets drawn into the return side. Over years, the damp marine air cements it inside boots and plenum insulation. We scope it, clean it, and seal the entry points.
- Mildew and dust-mite debris colonizing Lennox plenum insulation. The cool, damp marine air in Foster City keeps Lennox cased coils and plenum liners humid long after a cycle ends. That persistent moisture is what dust mites and mildew need to take hold inside duct liners. Cleaning removes the buildup; sealing ducts with quality aftermarket mastic keeps bay air from feeding it back.
- Torn flex at Lennox air handler collars. Many Foster City homes have original early flex runs through tight crawlspaces over engineered fill. Flex tears at the collar, letting in fill dust and moist crawlspace air. We replace the torn section, mastic-seal the joint, and then clean the supply side that’s been eating that debris.
- Blower wheels caked with gray fill silt. Lennox air handlers in tight Foster City crawlspaces pull in fine silt that packs onto the blower wheel and secondary heat exchanger passages. That cuts airflow and raises static pressure. Rotobrush agitation plus HEPA extraction cleans it out, and video inspection confirms the wheel is clear before we finish.
- Seam leaks and corrosion pits in early rigid metal Lennox trunk runs. 1960s and 1970s Foster City tract homes often have original rigid trunk-and-branch metal ductwork. Decades of bay-air moisture condensing inside cause seam leaks and corrosion pits, which drop delivered airflow to far ceiling registers. We find these with video inspection and seal what’s sealable, then give you a straight read if the trunk needs repair.
Lennox Service in Foster City: What Local Conditions Mean for Your Equipment
Foster City was built almost entirely on engineered fill in the 1960s and 70s, so nearly every home here sits on a raised slab or crawlspace in former marshland. Duct systems in Foster City accumulate a specific mix of salt-laden bay air moisture and fine lagoon silt that inland Peninsula cities like San Mateo or Redwood City simply don’t see. On a lagoon-side Foster City townhome, we pulled a Lennox Elite air handler whose blower wheel was caked with gray fill silt and whose return flex had torn at the collar, pushing bay-air moisture into the plenum. We ran video inspection through the ceiling-register plenum runs, cleaned the supply and return sides, replaced the torn flex, and mastic-sealed the boot joints. Delivered airflow at the far registers came back and the musty smell in the hallway cleared. What we pulled out of that system is the same gray silt and corrosion residue you’ll find in many Foster City Lennox systems near the lagoon. Once you cross over to the solid-ground tracts of San Mateo, that pattern drops off sharply. Duct cleaning here is as much about moisture and corrosion control as it is about dust.
Lennox Models & Products We Service in Foster City
We service the Lennox equipment commonly installed in Foster City homes: Merit Series gas furnaces, Elite Series furnaces and air handlers, Dave Lennox Signature Collection variable-speed air handlers, and the CBX-style cased evaporator coils paired with Merit and Elite condensers. For parts that affect fit and reliability, like coils, igniters, and control boards, we use quality parts that match the Lennox spec. For duct repair, we use quality aftermarket mastic, flex, and insulation where the OEM label adds nothing. On older Lennox furnaces and air handlers, we give a straight repair-or-replace read. If the heat exchanger or coil housing is corroded from Foster City moisture, sealing a failing system is throwing money at it.
See the difference
Before
After
Before
After
Before
AfterLennox Service Pricing in Foster City
Air duct cleaning in Foster City typically runs from $350 to $650 for a complete single-system home, and homes with two separate Lennox systems usually fall between $600 and $1,100. Extra return drops, severe corrosion, or extensive duct repair push the cost toward the higher end. The written estimate sets the final price before any work starts, so there is one flat price per system agreed up front. No per-vent pricing, no bait-and-switch. A free estimate includes a walkthrough, a scope of the duct layout, and a clear line-item quote. Call (855) 382-9257 for an exact quote – estimates are free.
Serving Foster City, CA – Our Local Coverage Area
We serve Foster City and nearby communities. Use the map below to see the area we cover. If you’re nearby, we can almost certainly help.
FAQs – Lennox Air Duct Cleaning in Foster City
Foster City homes sit on engineered fill in former marshland, and the fine gray silt that blows off lagoon-side fill gets drawn into Lennox return boots and plenums. The damp marine air keeps that silt wet long enough for mildew to form, which is the musty smell. Homes on the solid-ground tracts of San Mateo don’t have the same fill dust source or the same standing moisture pattern. We clean the supply and return sides, replace torn flex that’s letting fill dust in, and seal boot joints so it stays out.
Yes. Peeling foil-faced duct wrap on a 1990s or 2000s Lennox Merit furnace in a Foster City crawlspace is a moisture problem, not just a cosmetic one. When the wrap fails at the seam, bay-air moisture and fill dust enter the return side and get pushed through the supply boots. We replace the failed wrap, seal the joints, and then clean the rest of the system. If the underlying duct is corroded from years of crawlspace moisture, we’ll give you a repair-or-replace read before spending money on sealing a failing run.
Yes, in most cases. A CBX-style cased coil with accessible panels can be cleaned in place using Rotobrush agitation and Nikro HEPA extraction with negative-pressure containment. We scope the coil before and after to confirm the fins are clear. If the coil housing is heavily corroded from Foster City’s bay-air moisture, we’ll tell you plainly and discuss repair or replacement rather than cleaning a housing that’s about to fail.
Foster City’s cool, damp marine air and morning fog mean Lennox duct liners and plenum insulation stay humid longer than they do inland. That extended moisture window is what allows mildew and dust-mite debris to build up faster. Most Foster City Lennox systems benefit from a cleaning every 3 to 5 years, and lagoon-side homes with visible gray silt at the registers may want to scope their system sooner to see what’s accumulating. Call (855) 382-9257 and we’ll walk you through what your system actually needs based on a video inspection.
It does. Short plenum runs with boot joints at the ceiling collect debris right where the duct meets the register, especially in Foster City where bay-air moisture helps fine silt and lint stick to the boot edge. Over time, that restricts airflow to the far upstairs rooms. We pull the registers, clean the boot joints and plenum runs with Rotobrush, and re-scope so you can see the difference before and after.
Service Areas Near Foster City
We also serve homeowners in nearby San Lorenzo, Castro Valley, Walnut Creek, Danville, and Lafayette. If you’re close to Foster City and dealing with a Lennox duct system that needs real attention, call us and we’ll get it scoped and priced.
Book Your Lennox Service in Foster City Today
We clean, repair, and dry-vent service Lennox duct systems across Foster City, and we scope the work before and after so you can see what you paid for. Clean ducts don’t need a sales pitch – the before-and-after scope footage does that work. Call (855) 382-9257 for a free estimate. We answer 24/7. Fast dispatch from 7am to 7pm, Sunday through Friday.
Written by Frank Peralta, Owner at Duct Cleaning Castro Valley, serving Foster City since 2012.