Lennox HVAC Service Nationwide

Why Marietta Homeowners Choose Lennox HVAC

We provide independent Lennox in Marietta HVAC repair, maintenance, and installation, and we’ve worked on enough XC, EL, ML, and SLP units in this city to know their failure patterns cold before we even pull into your driveway. Most Lennox calls we run in Marietta come down to three things: evaporator coil leaks from humid attic air, variable-speed motor module failures after power surges, and blown control fuses on older Merit systems. We’re not an authorized Lennox dealer and we don’t pretend to be. What that means for you is simple: we repair what’s actually broken, use factory parts where they matter, and tell you straight when a repair isn’t worth your money. Call (478) 662-5175 and you’ll get a live person, not a phone tree.

Call (478) 662-5175

Lennox builds genuinely good equipment. The Dave Lennox Signature Collection, the Elite line, the Merit series. They’re efficient, quiet, and when installed right, they run for years. But Marietta’s climate works against them, which is why AC Repair expertise matters. Long humid summers push condensate through coils at a rate the engineers in Texas didn’t always account for. Surprise cold snaps in February send undersized ductwork in 1970s split-levels into overdrive. And late spring oak and pine pollen coats outdoor condenser coils like a wool blanket, cutting airflow and raising head pressure until the compressor gives up. Knowing how a Lennox ages in Marietta specifically, not just in general, is the difference between a one-visit fix and a season of callbacks.

Devin Marlowe, our owner, spent decades working on HVAC systems across the South and he’s logged more service calls in the Kennesaw Avenue corridor near Marietta Square than he can count. He knows the quirks of the older ranch and split-level homes in that part of town as well as anyone. When we send a technician to your Marietta home, they arrive with that same working knowledge, plus a written price before any tool comes off the truck.

Why Trust Brandt HVAC Co Marietta for Your Lennox HVAC?

Because our techs have rebuilt enough Lennox evaporator coils and trouble-shot enough GWM modulating gas valves to know exactly which failures are worth repairing and which aren’t, without any factory dealership strings attached. A dealership tech is under pressure to sell you a new system. We’re not. We make our money fixing things right the first time and earning your next call, not your next purchase.

We default to genuine Lennox OEM parts on anything touching the sealed system or heat exchanger. That means if your XC20 has a leaking coil or your SLP98V has a cracked heat exchanger, the replacement part comes from Lennox, not a “compatible” copy. Tolerances on variable-speed and modulating equipment are too tight for guesswork. But we’ll also tell you when an aftermarket cap, contactor, or ignitor will outlast the factory version, because sometimes the factory version was the problem in the first place.

Every Lennox repair we do in Marietta comes with a written guarantee. If it fails within the guarantee period, we return at no charge under our 365-Day Done Right Promise. No argument, no second invoice, no “well technically that’s a different part.” We also give you a written price before work starts, on every job, no exceptions. And the technician arriving at your door? You’ll know their name and see their photo before they get there, and they’ll show you a photo ID badge at the door. That’s the Threshold Verified standard we work under, and it’s non-negotiable. Opening your door to a stranger shouldn’t feel like a gamble.

Devin built his reputation on straight-forward diagnostics. He tells you exactly what’s broken, what it costs to fix, and what happens if you wait. That philosophy runs through every Lennox call we take in Marietta.

Common Lennox HVAC Problems We Fix in Marietta

Here’s what we actually see on Lennox equipment in this city, week after week:

• Leaking evaporator coils on XC20 and XC25 units. This is the big one. Lennox’s high-efficiency coils leak due to formicary corrosion, and Marietta’s humid attic air accelerates it. On a hot July afternoon, the coil sweats constantly. Add trace organic acids from household air and you get pinhole leaks. Symptom: the system runs but won’t keep up, and your tech keeps topping off refrigerant. If the unit is 10-plus years old, we’ll tell you replacing the coil is throwing good money after bad.
• Variable-speed blower motor module failures on XC/XP and SLP98V units. After a summer thunderstorm rolls through Marietta and the power flickers a few times, those ECM motors take a beating. The module burns out and the blower either won’t start or runs at one speed, full tilt. We replace the module, not the whole motor, which saves real money.
• Inducer motor bearing noise and pressure switch lockouts on EL296V furnaces. The inducer is the little fan that pulls combustion gases through the heat exchanger. When its bearings wear, you hear a high-pitched whine. When it fails to build enough pressure, the pressure switch trips and the furnace won’t ignite. Usually it’s fixable; occasionally the whole inducer assembly needs replacing.
• Condensate drain clogs on horizontal attic installations. Sludge builds up in the drain line, the overflow switch trips, and the unit shuts off even though nothing mechanical failed. In Marietta’s humidity, we see this constantly on attic-mounted Lennox air handlers. The fix is a drain flush and, on repeat offenders, a drain pan treatment.
• Blown 3-amp control fuses on Merit ML14 systems. The ML14 is a workhorse, but its low-voltage wiring can chafe. A rubbed-through wire touching the suction line blows the fuse and the whole system goes dark. We trace the low-voltage path, repair the harness, replace the fuse, and it runs fine. But finding the chafe is the hard part, and that’s exactly the kind of diagnostic patience we bring.

Lennox Parts & Our Repair-vs-Replace Approach

On the sealed system and heat exchanger, we use genuine Lennox OEM parts. Those components have exacting specs: refrigerant volume, air temperature rise, combustion gas clearance. An aftermarket copy that’s “close enough” usually isn’t. On wear items like capacitors, contactors, and ignitors, we’ll often install a proven aftermarket part because the factory version wasn’t designed to survive Georgia’s heat plus your attic’s added 30 degrees.

When a Lennox compressor is over 12 years old, or a coil is leaking on a 10-plus-year system, we’ll tell you straight. “This repair will cost X, and here’s the realistic lifespan left in this system.” Some homeowners want the repair anyway, and we’ll do it. But many appreciate knowing the score before spending $800 to patch a system that needs replacing in two seasons. That’s how we decide repair versus replace on Lennox equipment in Marietta: we tell you what we’d do if it were our house, with numbers, and you choose. Call (478) 662-5175 for an honest Lennox assessment.

Our Lennox Service Process – Step by Step

1. 1
   Listen and diagnose. Tell me what it’s doing, and I’ll tell you what it needs, no guesswork, no upsell. We start with your description and our own eyes, ears, and gauges. For a Lennox XC25 that’s short cycling, we check the inverter board. For an ML14 with no cooling, we walk the low-voltage path before touching the compressor.
2. 2
   Present the written price. Before any work starts, you see the number in writing. Parts and labor, itemized. No work begins without your sign-off.
3. 3
   Repair or install. We use OEM parts where it matters. For AC repair on Lennox equipment in Marietta, most jobs finish in one visit. Furnace repair is often the same day, unless a special-order part for an older EL296V needs to ship.
4. 4
   Test under load. We don’t just clear the code and leave. We run the system long enough to confirm the fix holds. Our tech pulled up to a 2016 Merit ML14 in East Cobb with no cooling and a 3-amp control fuse blown. After walking the low-voltage path, we found the crankcase heater wire chafed against the suction line, rubbed through the insulation. We stripped back the harness, heat-shrinked the conductor, replaced the fuse, and wrapped the rub point. The unit fired right up and pulled 68 amps for 20 minutes without a hiccup. That’s what a proper test looks like.
5. 5
   Warranty in writing. Every repair gets a written guarantee. If it fails within the guarantee period under our 365-Day Done Right Promise, we return at no charge. Simple as that.

Lennox Products We Service & Install in Marietta

We work on the full residential Lennox lineup. The Dave Lennox Signature Collection, including the SLP98V variable-speed gas furnace and the XC20/XC25 variable-capacity air conditioners. The Elite Series, including the EL296V two-stage furnace. The Merit Series, including the ML14 single-stage air conditioner and companion gas furnaces. We also service and install Lennox service in Mableton and Marietta ductless mini-split systems, which are increasingly popular in additions and converted garages where running ductwork from a 1960s ranch isn’t practical. We carry common Lennox capacitors, contactors, ignitors, pressure switches, and blower motor modules on our trucks for same-day repair. Special-order OEM coils, heat exchangers, and inverter boards typically arrive within a few business days.

We Also Service These Brands

We’re Lennox specialists, but we’re not Lennox-dependent. Our techs service Carrier and Trane systems with the same depth of experience, plus Goodman, Rheem, York, Daikin, Bryant, and American Standard. If your home has a mix of brands, or you’re replacing a Lennox with something else, we’ll give you straight answers across the board. Our recommendation follows the house, the ductwork, and your needs, not a dealership quota.

FAQs – Lennox HVAC Service in Marietta

Is Brandt HVAC Co Marietta authorized by Lennox? No, we’re an independent Lennox service provider. That means no factory quotas, no pressure to sell new equipment, and no restrictions on what we can honestly tell you. We work on Lennox systems because we know them inside and out, and because they’re common in Marietta homes.

Do you use genuine Lennox/OEM parts? Yes, on the sealed system and heat exchanger, always. For wear items like caps, contactors, and ignitors, we use either OEM or a proven aftermarket part, whichever will last longer in your system. We’ll tell you which we’re using and why. Call (478) 662-5175 with your model and symptom and we’ll give you a straight answer.

How long does Lennox service take? Most AC repairs on Lennox equipment in Marietta finish in one visit, typically two to four hours including diagnosis and testing. Furnace repairs are similar, unless a specific OEM part for an older EL296V or SLP98V has to be ordered. Installations take a full day or two depending on system type and ductwork condition.

What Lennox models and series do you cover? We service the full residential range: Dave Lennox Signature Collection XC/XP and SLP98V, Elite Series including EL296V, Merit Series including ML14, and Lennox ductless mini-splits. If it says Lennox and it heats or cools a Marietta home, we’ve likely repaired it.

Will service void my Lennox warranty? No. As long as repairs are done competently and with OEM parts where required, your Lennox factory warranty remains intact. We document every repair, keep records for warranty purposes, and can work with you on any warranty claim filings.

How much does Lennox HVAC repair cost in Marietta? AC repair on Lennox service in Acworth and Marietta systems typically runs $150 to $650, furnace repair $150 to $700, and a full Lennox AC installation $3,500 to $7,500. A tune-up runs $80 to $200. Here’s the breakdown:

Call (478) 662-5175 for an exact quote on your Lennox system. Written estimate before any work starts, always.

Why does my Lennox XC25 condenser fan keep running after the outdoor unit shuts off? That’s usually the inverter board’s post-purge cycle doing its job, not a fault. Variable-speed systems run the fan briefly after cooling stops to purge residual refrigerant and equalize pressures. If it runs for more than a few minutes, or starts and stops erratically, it could be an inverter board fault, and that’s worth a diagnostic call.

I hear a high-pitched whine from my Lennox EL296V furnace inducer. Can it be lubricated? No. Modern inducer motors have sealed bearings. The whine means bearing wear, and lubrication won’t fix it. Sometimes the entire inducer assembly needs replacing. If the pressure switch also starts tripping, the inducer is no longer pulling enough draft, and that’s a repair we usually complete the same day.

My Lennox Merit ML14 keeps tripping its 3-amp fuse every few days. What’s the usual cause? A chafed low-voltage wire is the most common culprit we find in Marietta. Vibration or poor routing causes the insulation to rub through against the suction line or chassis, the wire shorts, and the fuse blows. Replacing the fuse alone won’t fix it, the rub point has to be found and repaired, which takes diagnostic time but solves the problem for good.

Can you recharge my Lennox XC20 with R-410A if it uses the new R-454B refrigerant? No, those refrigerants are not interchangeable. If your XC20 was manufactured for R-410A, that’s what we use. If it’s a newer unit designed for R-454B, we use R-454B. Putting the wrong refrigerant in will destroy the compressor. We check the nameplate every time. If your system is low on charge, that means there’s a leak, and we find it before adding refrigerant.

How often should a Lennox SLP98V variable-speed furnace be tuned up in Marietta? Once a year, in the fall before heating season. The SLP98V’s modulating gas valve and variable-speed blower need annual attention to maintain efficiency and catch issues like a cracked heat exchanger or failing inducer before they leave you cold. Our tune-ups run $80 to $200 and include a written report of what we found. Call (478) 662-5175 to schedule.

Book Your Lennox Service in Marietta, GA

If your Lennox system is acting up in Marietta, call (478) 662-5175. A live person answers, 24 hours a day, seven days a week. We’ll schedule your visit, send you the technician’s name and photo before arrival, and start with a written price on every job. No guesswork, no upsell, just a Lennox system that works like it should.

Written by Devin Marlowe, Owner at Brandt HVAC Co Marietta, serving Marietta and the surrounding area.