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Get your free estimateLennox Ductwork Repair: The Alpharetta Owner’s Guide
Lennox ductwork repair in Alpharetta typically runs $150 – $650 depending on what failed and how much of the duct run needs attention. We stock common Lennox-compatible duct fittings, collars, dampers, and sealants on our trucks, so most repairs are completed same-day. The usual giveaway that ductwork has failed is a room that never reaches temperature, a spike in your electric bill, or dust settling on surfaces within days of cleaning. In Alpharetta’s humidity, failed duct seals also sweat, and that condensation finds its way into drywall and insulation. Marco Benitez and our crew see it most often in older Windward-area homes where the original flex duct was undersized from the jump.
Key Takeaways:
- Most Lennox ductwork repairs in Alpharetta fall between $150 and $650 installed.
- A failed duct joint or torn flex run quietly inflates your power bill by 20 – 30% before you notice the temperature difference.
- We write the price before any work starts, and the repair carries a full-year written guarantee.
- Same-day service is realistic for most duct failures; call (229) 537-2086 and a live person answers.
Which Lennox Models This Applies To
Ductwork is not model-specific the way a control board or inducer motor is, but Lennox systems do have quirks that matter. Lennox residential equipment in Alpharetta spans the Merit, Elite, and Signature series, and the ductwork attached to them was often sized to the installer’s convenience rather than the manual J load calculation those systems deserve. A 3-ton Lennox Elite paired with duct sized for a 2.5-ton system will pull high static pressure, blow out weak joints, and shorten blower motor life. We identify what you have by measuring the plenum opening, taking static pressure readings, and checking the R-value of the existing flex or duct board. For Lennox specifically, we default to OEM-spec duct components when the failure involves the supply plenum or return drop, but we are candid when a quality aftermarket collar or damper does the same job for less money. Dalton Heating & Air Alpharetta is an independent service provider, not affiliated with Lennox. We also stock parts for Carrier and Trane systems, so mixed-brand homes are not a problem.
Styles & brands we work with







Signs Your Lennox Ductwork Repair Is Failing
- One room runs 5 – 8 degrees warmer than the rest of the house. A disconnected or crushed flex run is starving that room of conditioned air. The longer it stays that way, the harder your Lennox blower works against a restriction it was never designed to handle.
- Dust returns to furniture within 48 hours of cleaning. A breached return duct is pulling attic air and insulation particles into the conditioned space. In Alpharetta, that attic air is also carrying whatever the Georgia humidity breeds up there.
- You hear a soft whistle or flutter when the system cycles. Air escaping through a failing seam or torn duct liner makes that noise. It usually gets worse as the system runs longer cycles in July and August.
- Your electric bill jumped without a change in usage. Leaky ducts mean your Lennox unit runs longer to hit setpoint. A 25% duct leak is enough to add $40 – $70 a month to a summer power bill in Alpharetta.
- Condensation or water stains appear on a ceiling near a register. In Georgia humidity, cold air hitting a leaky duct collar creates sweat. That moisture wets the drywall, and you now have a duct repair plus a drywall repair.
See the difference
Before
After
Before
After
Before
AfterReplacement Cost & What’s Included
Most Lennox ductwork repairs in Alpharetta land between $150 and $650, with the spread driven by accessibility and how much duct run actually failed. A collapsed flex run in an open attic is on the lower end. A failed supply plenum connection behind a finished ceiling pushes higher because of the access work. Here is what the price covers, in writing, before any wrench turns:
- Basic duct seal and collar repair: $150 – $300. Includes mastic sealing, new collars where needed, and static pressure verification.
- Flex duct run replacement: $250 – $450 per run, depending on length and R-value. We use R-8 flex for attic runs in Alpharetta, which is what this climate demands.
- Supply plenum or return drop repair: $300 – $650. Includes sheet metal fabrication, sealing, and airflow verification across the full duct system.
Every repair includes the written 365-Day Done Right Promise. If the work fails within that year, we return at no charge. That is a non-negotiable term of The Garrison Standard, not an upsell.
DIY or Call Us?
Here is the honest split. You can safely inspect the visible ductwork in your attic or crawlspace. Look for disconnected flex runs, crushed sections, and oily-looking stains around joints where air has been leaking. You can also check that registers are open and unobstructed. What you should not do is climb into an attic on a 95-degree Alpharetta afternoon and start pulling duct apart. That is how heat exhaustion and a bigger repair bill happen. Ductwork repair is not high-voltage work, but it does require static pressure testing and proper mastic application to actually hold. A duct that is taped but not mastic-sealed will fail again within a season.
If you have already found the problem and want it fixed today, call (229) 537-2086. We will tell you over the phone what the likely fix costs, and the price gets confirmed in writing before work begins.
FAQs
Flex duct in an Alpharetta attic typically lasts 15 – 20 years before the inner liner delaminates or the outer jacket fails, but that assumes it was sized and hung correctly in the first place. Under-sized runs and poorly supported spans shorten that lifespan significantly.
Yes, in most cases. Torn outer jackets, failed seams, and disconnected collars are all repairable with mastic and proper fittings. Full replacement only makes sense when the inner liner has degraded or the run was under-sized from the start. We will tell you which is which before quoting anything.
A typical repair takes 2 to 4 hours from arrival to cleanup. That includes static pressure verification before and after the repair so you can see the actual improvement, not just hear about it.
We stock common collars, dampers, mastic, R-8 flex duct, and sheet metal for plenum repairs on every truck. If your repair requires a non-standard fitting, we fabricate it the same day in most cases. Call (229) 537-2086 with your specific issue and we will confirm before we roll.
Written by Marco Benitez, Owner, Dalton Heating & Air Alpharetta at Dalton Heating & Air Alpharetta, serving Alpharetta and nearby areas.