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Get your free estimateWhy Jacksonville Homeowners Choose Lennox HVAC
Lennox HVAC service in Jacksonville is what we do every day, and we do it as an independent provider, not a factory-authorized dealer. That matters because we have no quota pushing us to sell you a new unit when a $200 repair gets the job done. Devin Marlowe and our techs see hundreds of Jacksonville Lennox service calls each season, which means we know exactly which parts fail in this heat and salt air and how to fix them fast. If your Lennox system is acting up, call (904) 456-0205 and we’ll give you a written price before any work starts.
Lennox builds some of the most efficient residential HVAC equipment on the market. The XC25 can hit 26 SEER. The SLP98V furnace modulates gas flow from 35% to 100%. These are sophisticated machines, and they demand a tech who understands their communicating protocols and sealed-system tolerances. That’s the service we bring to Jacksonville.
Why Trust Brandt HVAC Co Jacksonville for Your Lennox HVAC?
We are factory-trained on Lennox’s proprietary communicating systems. That includes the iComfort S30 thermostat ecosystem, which is not just a thermostat. It is the brain that talks to the outdoor unit, the indoor air handler or furnace, and the zoning dampers. When that communication breaks down, the system throws codes and misbehaves in ways that stump techs who only know basic controls. Our team knows those codes.
Devin learned the trade at Los Angeles Trade-Technical College and spent nearly two decades working on everything from rooftop package units to tired split systems before bringing that experience to Jacksonville. He built Brandt HVAC around one rule: tell the homeowner exactly what is wrong, exactly what it costs, and exactly what the work covers. No fine print, no surprise invoices. Know what it is, know what it costs, know it’s covered, that’s the whole deal.
We are not authorized by Lennox, and we will never pretend otherwise. What we offer is hands-on repair data that independent shops rarely compile. We track failure patterns across Jacksonville neighborhoods, from Riverside to Lennox in Jacksonville Beach, and that local data makes our Lennox diagnostics faster and more accurate.
Styles & brands we work with







Common Lennox HVAC Problems We Fix in Jacksonville
Lennox equipment is well-built, but Jacksonville throws two punches at it: relentless humidity and salt-heavy coastal air. Here are the failures we see most often, in real homes across the city.
- Compressor burnout from short-cycling on XC/EL Elite Series units. The iComfort S30 thermostat sometimes drops its communication signal to the outdoor unit. The compressor kicks on, shuts off, kicks on again. That short-cycling overheats the compressor windings and eventually kills the compressor. The fix is often a firmware update and a wiring check, not a compressor replacement, but only if you catch it early.
- Condenser coil corrosion from Jacksonville salt air. Even Lennox’s aluminum fins corrode faster near Atlantic Beach and Mayport than inland. When the coil gets pitted and flaky, heat transfer drops and the unit runs longer to hit setpoint. We clean and treat coils annually, and when corrosion is too deep, we recommend a coil replacement before the compressor gets stressed.
- ECM blower motor failure in EL296V furnaces after power surges. Jacksonville gets a lot of thunderstorms. The variable-speed ECM motor in the EL296V is sensitive to voltage spikes. When that motor fails, the furnace may still light but the blower won’t spin, or it runs at one speed only. A surge protector on the furnace circuit is cheap insurance we recommend on every Jacksonville install.
- Refrigerant leaks at the evaporator coil brazed joint on XC21 models. We see this enough that we check that specific joint on every XC21 we service. The braze can develop a hairline crack over years of thermal expansion. A slow leak means the system loses cooling capacity gradually, and the homeowner compensates by dropping the thermostat lower until the compressor starts struggling.
- Failed run capacitors on Merit Series heat pumps like the ML14XP1. Capacitors are consumable parts. They fail more often in Jacksonville because heat pumps run almost year-round. We replace them with OEM Lennox dual capacitors, verify the charge and subcooling, and send the homeowner a photo of the old part with the new specs listed.
Lennox Parts & Our Repair-vs-Replace Approach
For communicating components and sealed-system parts, we use OEM Lennox parts. That means compressors, inverter boards, the iComfort S30 thermostat, evaporator coils, and expansion valves come from Lennox. For non-communicating wear items like capacitors, contactors, and blower motors, we offer high-quality aftermarket options when they meet or exceed OEM specs, and we tell you the difference in plain language before you choose.
We stock common Lennox capacitors, contactors, pressure switches, and igniters on our trucks, which means most AC Repair and furnace repair jobs in Jacksonville are done same-day. For proprietary boards and coils, we source from local distributors usually within a day or two.
When a Lennox unit is over 12 years old and the compressor or heat exchanger fails, we give you an honest replacement quote before recommending a repair. Spending $2,800 to replace a compressor on a 14-year-old ML14XP1 rarely makes sense. We will tell you that plainly, show you the numbers, and let you decide.
Our Lennox Service Process – Step by Step
- 1
Diagnosis. We pull fault codes from the iComfort S30 or the furnace control board, check refrigerant pressures, electrical readings, and airflow. You get a written price for the repair before we touch a wrench.
- 2
Repair. We use OEM Lennox parts for anything that talks to the system or holds refrigerant. We photograph the failed part and the new one so you can see exactly what changed.
- 3
Test. We run the system through a full heating or cooling cycle, verify the temperature split, and confirm the communicating controls are talking properly. Last week our tech diagnosed an XC21 heat pump in Mandarin blowing warm air. The iComfort S30 showed a compressor lockout, and we found the run capacitor reading 15µF instead of 35µF. We swapped in an OEM Lennox dual capacitor, verified subcooling, and had the system back to a 19°F delta within the hour.
- 4
Warranty. Every repair includes a written guarantee. If it fails within the guarantee period, we return at no charge under the 365-Day Done Right Promise. No argument, no additional fee.
See the difference
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After
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Before
AfterLennox Products We Service & Install in Jacksonville
We service and install the full Lennox residential lineup, including the XC series (XC21, XC25), the Elite EL series (EL18XCV, EL296V), the Merit ML series (ML14XP1), the SLP98V variable-capacity furnace, and the Dave Lennox Signature Collection with the S30 thermostat ecosystem. If your Jacksonville home has a Lennox heat pump, a gas furnace plus AC split system, or a hybrid dual-fuel setup, we know it. We also handle Lennox air filtration systems, including the Healthy Climate line, and we stock replacement media locally.
We install new Lennox systems in Jacksonville with a written fixed price, a set install date, and all rebate and financing paperwork handled before the first truck rolls.
We Also Service These Brands
Most Jacksonville homes have one of a handful of brands, and we are not married to any of them. We service Carrier and Trane systems with the same written-price policy and the same 365-Day Done Right Promise. If your home has a Carrier Infinity or a Trane XR series, we will treat it with the same care we give a Lennox XC25.
FAQs – Lennox HVAC Service in Jacksonville
No. We are an independent Lennox service provider, not a factory-authorized dealer. That means we answer to you, not to Lennox. We still use OEM Lennox parts for all communicating and sealed-system components, and our techs are factory-trained on Lennox equipment. Being independent just means we can tell you the truth about repair versus replace without a sales quota in the room.
Yes, for all communicating components and sealed-system parts. That includes compressors, inverter boards, the iComfort S30 thermostat, evaporator coils, and expansion valves. For non-communicating wear items like capacitors and contactors, we offer quality aftermarket options that meet or exceed OEM specs and explain the difference before you decide. Call (904) 456-0205 for a written quote on any Lennox repair.
Most Lennox AC repairs in Jacksonville are done same-day. We stock common capacitors, contactors, igniters, and pressure switches on our trucks. For proprietary boards and coils, we usually have the part within one to two days from local distributors. When you call (904) 456-0205, we will tell you what we can do before you hang up.
We service and install the full residential Lennox lineup: XC and EL Elite Series, ML Merit Series, SLP98V variable-capacity furnaces, and the Dave Lennox Signature Collection with the S30 thermostat. If your Jacksonville home has a Lennox heat pump, dual-fuel system, or a communicating zoning setup, we have seen it before.
No. Using an independent contractor does not void your Lennox manufacturer warranty, as long as the work is done correctly and documented. We use OEM Lennox parts where the warranty requires them, and we keep service records you can submit to Lennox if you ever need a factory claim. We also register new Lennox equipment warranties for our installation customers.
Here are the price ranges we quote for Lennox work in Jacksonville:
| Service | Typical Price Range |
|---|---|
| AC Repair | $150 – $650 |
| Furnace Repair | $150 – $700 |
| AC Installation | $3,500 – $7,500 |
| Tune-Up | $80 – $200 |
| Capacitor Replacement | $150 – $300 |
| Refrigerant Recharge | $250 – $650 |
Every job starts with a written price before any work begins. Call (904) 456-0205 for an exact quote on your Lennox system. Estimates are free.
A lockout code on an SLP98V usually means the furnace control board detected a safety issue and shut the burners down. The most common causes in Jacksonville are a dirty flame sensor, a blocked condensate drain, or a failing pressure switch. The fix is often a cleaning and a part under $50. It can also indicate a more serious issue, so call (904) 456-0205 and we will read the exact code and tell you what it means.
Not necessarily. A tripping breaker on an XC25 is more often caused by a failing dual capacitor, a grounded compressor contactor, or a wiring short than by the compressor itself. We diagnose the circuit before condemning the compressor. That saves Jacksonville homeowners thousands in unnecessary replacements.
We can, but only after we find and fix the leak. Adding refrigerant to a system with a known leak just wastes your money. On ML14XP1 models in Jacksonville, we most often find the leak at the evaporator coil brazed joint or a rub-out on the suction line. We repair the leak, pressure-test with nitrogen, pull a proper vacuum, and then recharge to the manufacturer’s specified subcooling. Call (904) 456-0205 for a written quote.
A constantly running blower on an EL296V is usually a thermostat setting issue, not a furnace problem. The iComfort S30 or a standard thermostat may be set to “circulate” mode, which runs the fan on a schedule. If the settings are correct, the likely culprits are a stuck blower relay or a failing ECM motor control module. We can tell you which one it is in about 20 minutes.
In Jacksonville, we recommend every 30 to 60 days during the cooling season, which runs from May through October. Our humidity loads the filter with more particulates, and a dirty filter restricts airflow, raises static pressure, and can trigger freeze-up codes on Signature Series air handlers. If you have the Healthy Climate filtration system, follow the indicator or change media every 6 to 12 months depending on your home’s dust load.
Book Your Lennox Service in Jacksonville, FL
If your Lennox system is not keeping your Jacksonville home comfortable, call (904) 456-0205. A live person answers, day or night. We will send a background-checked, uniformed technician whose name and photo you receive before arrival. You get a written price before any work starts, and a written guarantee on every repair. That is the whole deal.
Written by Devin Marlowe, Owner at Brandt HVAC Co Jacksonville, serving Jacksonville since moving here from Los Angeles after nearly two decades in the trade.