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GoodmanSeasonal tune-up and full diagnostic on your Carrier, Trane, or Goodman system - readings shown to you before any repair is proposed
Diagnosis first, numbers second - you approve the repair price before a single part goes in.
Get your free estimateWhy San Antonio Homeowners Choose Lennox HVAC
We provide independent San Antonio Lennox service and repair across the area, from downtown bungalows to the sprawling subdivisions on the far northwest side. Our techs work on Lennox’s G26, G61, XC21, and SL280 series daily, and we’ve developed specific diagnostics for their variable-speed inverter boards and communicating controls without relying on Lennox’s authorized network. That means faster diagnosis and a straight answer on what the repair costs before any work starts. Call (361) 470-8872 and a live person answers, day or night.
Lennox builds solid equipment, but San Antonio’s climate punishes it in ways the manufacturer’s manual never mentions. We’re an independent Lennox service provider, not an authorized dealer, and that’s a distinction that works in your favor: we answer to you, not to a corporate service quota. Devin Marlowe, our owner, learned the trade at Los Angeles Trade-Technical College and has spent the better part of two decades working on HVAC systems across the Southwest. His crew has been running Schertz Lennox service calls and throughout San Antonio for years, including plenty of long summers keeping homes near the Pearl District comfortable when the heat index climbs past what feels survivable.
Why Trust Brandt HVAC Co San Antonio for Your Lennox HVAC?
Lennox equipment has quirks that only reveal themselves after hundreds of service calls. The iComfort S30 thermostat, for example, will occasionally lose communication with the outdoor unit and throw a lockout code that sends other techs chasing ghosts. We know the sequence. We check the communicating wire first, then the board, then the firmware version. It’s methodical, and it saves you from paying for parts you don’t need.
Devin’s rule on parts is simple: if it’s a capacitor, ignitor, or pressure switch for a common Merit or Elite model, we stock the Lennox OEM part on the truck. If it’s a control board with a five-day OEM lead time, we’ll have an honest conversation about a high-grade aftermarket alternative before we install anything. You approve every part and every price in writing before work begins. No exceptions. Every repair also carries a written guarantee, and if the same failure returns within the guarantee period, we come back at no charge under our 365-Day Done Right Promise.
You’ll know exactly who’s walking through your door. We send the technician’s name and photo before every visit, and they’ll show a photo ID badge at the door. That’s the Threshold Verified standard, and it matters when you’re home alone or have kids in the house.
Styles & brands we work with
Common Lennox HVAC Problems We Fix in San Antonio
- XC21 inverter drive board failures after storms. The XC21 and XC25 air conditioners use an inverter compressor that varies speed based on cooling demand. The drive board is sensitive to power surges, and San Antonio’s Hill Country thunderstorms send lightning through lines all summer. We see burnt relays and blown capacitors on these boards regularly in northwest-side neighborhoods. The fix is an OEM board, not a band-aid capacitor swap.
- SL280V variable-speed inducer noise and pressure-switch trips. San Antonio’s hard water leaves mineral deposits in condensate lines and inducer housings. On the SL280V and SLP98V furnaces, that scale builds up until the inducer motor runs rough, gets loud, and eventually trips the pressure switch. We clean the housing, verify condensate drainage, and replace the inducer when the bearings are too far gone. The hard water will keep doing this, which is why a fall furnace tune-up matters here.
- iComfort S30 communication lockouts in humid shoulder seasons. The iComfort S30 thermostat talks to the outdoor unit over a serial communication line. Humidity and slight voltage fluctuations during San Antonio’s spring and fall can corrupt that signal, causing random lockouts and no-cool calls. We’ve developed a diagnostic sequence that isolates whether it’s the stat, the wire, or the outdoor control board. Most fixes don’t require replacing the thermostat.
- G61 and G71 gas valves sticking closed after idle periods. In neighborhoods like Spring Branch and far northwest San Antonio where winter furnace use is intermittent, the gas valve on older G61 and G71 furnaces can stick closed after months of disuse. The symptom is a furnace that tries to ignite, clicks, and shuts down. We test the valve’s solenoid resistance, confirm gas pressure, and replace the valve when it’s dead. It’s a $150 – $700 repair depending on the valve and labor.
- Pitted condenser fins from hail and oak pollen clogging coils every spring. San Antonio’s spring brings hail and a thick coat of oak pollen. On 10-SEER Lennox condensers still running after 20-plus years, the fins are often pitted from hail and the coil is packed with pollen, which drives up head pressure and kills efficiency. We clean the coil, straighten fins where possible, and tell you honestly when it’s time to consider a new system instead of another recharge.
Lennox Parts & Our Repair-vs-Replace Approach
We stock Lennox OEM capacitors, ignitors, and pressure switches for common Merit and Elite models. When an OEM control board has a lead time longer than five days, we’ll offer a high-grade aftermarket universal board, but only with your written approval. We won’t quietly substitute parts and hope you don’t notice.
For Lennox units over 12 years old with a failed compressor or heat exchanger, we compare the repair cost against a new mid-tier Lennox replacement rather than pushing band-aid fixes. A compressor replacement on an aging XC21 might run $2,500 or more. A new ML14XP1 heat pump installed starts around $3,500. Sometimes the smarter money is on new equipment with a fresh manufacturer warranty. We’ll give you real numbers and let you decide. Call (361) 470-8872 and we’ll walk you through it.
Our Lennox Service Process – Step by Step
- 1
Diagnostic. We connect to Lennox communicating systems with the proper protocol, check stored fault codes, and test the component under load. For an XC21 throwing a compressor overcurrent fault, we don’t just reset the code and leave. We find out why the board tripped.
- 2
Written quote. You get a written price for parts and labor before anything comes apart. No work starts without your signature. That’s how Devin runs every job, and it’s non-negotiable.
- 3
Repair or replacement. We install the part, use Lennox subcooling charts for refrigerant work, and verify every electrical connection. On a refrigerant recharge, that means weighing in the correct charge, not just topping off until the line feels cold.
- 4
System test. We run the system through a full cycle, measure temperature splits, check amp draw, and confirm the unit isn’t fighting itself. On a recent Terrell Hills call, we pulled a 19-degree delta across the coil after a board replacement. That’s the standard, not the exception.
- 5
Written guarantee. Every repair includes a written guarantee stating what’s covered and for how long. If the fix fails within the guarantee period, we return free of charge under the 365-Day Done Right Promise.
See the difference
Before
After
Before
After
Before
AfterLennox Products We Service & Install in San Antonio
We service and install across the full residential Lennox lineup. On the AC repair side, the Elite Series XC21 and XC25 variable-capacity units are the ones we see most often in San Antonio’s newer subdivisions. Their inverter boards and communicating controls take a beating here. On the furnace side, the Signature Series SL280V and SLP98V high-efficiency units, plus the Dave Lennox Signature Collection SLP99V, show the hard-water effects we described earlier. The Merit Series ML14XP1 and ML17XP1 heat pumps round out the budget-conscious end, and they’re solid machines when installed and sized correctly. We stock common Lennox OEM capacitors, ignitors, and pressure switches locally so we’re not waiting on a warehouse for a routine fix.
We Also Service These Brands
Lennox is a big part of our work, but not the whole job. We service and repair Carrier and Trane systems too, and we’re comfortable diagnosing any major residential brand, including Goodman, Rheem, York, Daikin, Bryant, and American Standard. If it moves heat and air, our techs have probably already fixed one this month.
FAQs – Lennox HVAC Service in San Antonio
No, and we’re upfront about that. Brandt HVAC Co San Antonio is an independent Lennox service provider, not an authorized dealer or agent. What you get with us is independence: we recommend the repair that’s right for the equipment, not the one a manufacturer’s service agreement tells us to push. We use OEM parts where they matter and aftermarket parts only when you approve them in writing.
For capacitors, ignitors, and pressure switches on common Merit and Elite models, yes. We stock those Lennox OEM parts on our trucks. For control boards where the OEM lead time exceeds five days, we’ll offer a high-grade aftermarket universal option, but only with your written approval and a clear explanation of the trade-off. Your call, every time.
Most Lennox diagnostic visits take 45 to 90 minutes on site. Typical repairs like a capacitor replacement or ignitor swap are done same day from our truck stock. Control board replacements or inverter drive repairs might take a few days if the OEM part isn’t local. We’ll give you a straight answer on timing before we start, not after we’ve taken your unit apart. Call (361) 470-8872 for an exact quote; estimates are free.
We work on everything from the Merit Series ML14XP1 and ML17XP1 heat pumps through the Elite Series XC21 and XC25 air conditioners, and the Signature Series SL280V, SLP98V, and SLP99V furnaces, plus Lennox repair in Cibolo and surrounding areas. If you have a G26 or G61 from the 1990s or 2000s still running, we service those too, though we’ll have an honest conversation if a repair stops making financial sense.
No. Independent service and maintenance does not void a manufacturer warranty. What voids warranties is improper installation, using non-approved parts that damage the system, or skipping maintenance so the unit fails from neglect. We document everything we do, use OEM parts where they matter, and keep records that support any warranty claim you need to file. Your warranty stays intact.
Most Lennox repairs fall between $150 and $650 depending on the component and the system. A capacitor replacement runs $150 – $350. A refrigerant recharge for R410A systems runs $200 – $650. A furnace tune-up is $80 – $200. Here’s the line-item breakdown:
| Service | Typical Price Range |
|---|---|
| Lennox capacitor replacement | $150 – $350 |
| Lennox refrigerant recharge (R410A) | $200 – $650 |
| Lennox AC repair diagnostic + common fix | $150 – $650 |
| Lennox furnace tune-up | $80 – $200 |
Call (361) 470-8872 for an exact number on your system. The quote is free, and it’s in writing before any work begins.
That’s almost always a compressor drawing too many amps at peak load, often due to a failing inverter drive relay, a clogged condenser coil, or a capacitor that’s drifted out of spec. In San Antonio’s July and August heat, the system works hardest in the late afternoon, and any weakness shows up as an overcurrent condition. We check the start components, coil condition, and line voltage first, then test the compressor itself. If the compressor’s winding resistance is out of range, we’ll be straight with you about repair versus replacement. Call (361) 470-8872 and we’ll diagnose it same day.
You can, but it’s rarely the right financial call. A compressor replacement on a 15-year-old Elite system typically runs $1,800 to $2,800 parts and labor. That’s money going into a machine with a heat exchanger, coils, and electrical components all aging at the same rate. A new mid-tier Lennox system installed starts around $3,500 and carries a fresh manufacturer warranty. We’ll show you both numbers side by side and give you our honest recommendation, not whichever option pays us more. Call (361) 470-8872 for a written quote on both paths.
Error code 292 on an SLP98V indicates the variable-speed inducer motor has failed to reach or hold its commanded RPM. In San Antonio, we see this most often from mineral buildup from hard water restricting condensate drainage, which backs up into the inducer housing and drags the motor. It can also be a failing inducer motor itself or a blocked pressure switch hose. We check drainage first, then the motor’s performance under load. If the motor’s dead, we replace it with an OEM unit and verify the condensate path is clear so it doesn’t happen again in a year. Call (361) 470-8872 and we’ll get it diagnosed.
Annually, at minimum, before the cooling season starts. San Antonio’s heat pumps run hard from May through September, and a unit that’s even slightly low on R410A works harder and cools worse. We check subcooling and superheat against Lennox’s charging charts as part of every tune-up, and we only add refrigerant after verifying there’s no leak. If we find a leak, we find the leak, repair it, and recharge to spec, not just top it off. A heat pump tune-up runs $80 – $200. Call (361) 470-8872 to schedule yours before the first heat wave.
No, that’s not normal behavior, and it usually points to a failing backup battery in the thermostat, a loose communicating wire connection, or a control board that’s getting flaky. In San Antonio, our frequent thunderstorms cause enough power blinks that we see this on a weekly basis. We check the stat’s internal battery first, then the wire connections at both ends, then the outdoor control board. The fix is usually a battery or a tight wire, not a new thermostat. If it is the board, we’ll show you the fault and quote the replacement before we do anything. Call (361) 470-8872 and we’ll sort it out.
Book Your Lennox Service in San Antonio, TX
Tell me what’s wrong, I’ll tell you what it costs, and we’ll get your house back to livable. That’s the way Devin Marlowe has always run this company. Call (361) 470-8872 now. A live person answers 24/7, no phone trees, no voicemail. You’ll get a written price before any work starts, and our 365-Day Done Right Promise on every repair.
Written by Devin Marlowe, Owner at Brandt HVAC Co San Antonio, serving San Antonio since 2003.