(904) 512-0091

San Marco’s Local HVAC Company

San Marco HVAC & AC Repair

Upfront pricing from a crew that knows what low ground does to equipment. The local AC company for San Marco, St. Nicholas, Empire Point and the Southbank: air conditioning repair and installation, mini splits, duct work and furnace repair, all from one crew.

Limited‑time offer

HVAC Refresh & Tune‑Up

Cannot be combined with any other offer. One per household.

Claim This Offer$99

Get Your Free Estimate

Tell us what’s going on — we’ll get back to you in a flash.

    The Great Dane difference

    San Marco’s AC Company on the Low Ground

    More than 20 years keeping Jacksonville and Duval County comfortable, one honest repair at a time — and enough seasons down here to know what the water does and what it does not. A family company with upfront pricing, comfort techs who treat your home like their own, and a soft spot for shelter dogs.

    Heating & Cooling Services

    What Comes With a San Marco AC Service Call

    We Know This Ground

    San Marco is a short run and a familiar one, and down here the address tells you a good deal before anybody opens a panel — how the lot sits, where the equipment ended up, what has been through it already.

    Licensed & Insured

    Florida state certified contractor CAC036942, fully insured, and accredited with the Better Business Bureau at an A+ rating. Every tech who pulls into your driveway works under that license.

    20+ Years in Service

    Two decades across Duval County, which down here means having seen what a bad season does and what it does not. The people who answer your call are the same people who show up at your door.

    Every Job Gives Back

    We’re a proud supporter of the Jacksonville Humane Society. Part of what you spend keeping your home comfortable helps shelter dogs here in Jacksonville find one of their own.

    No cost, no pressure

    Get a Free Estimate on Your System

    Tell us what it’s doing. We find the real problem, give you the whole number before any work starts, and tell you straight if a repair is not worth your money.

    • A full diagnosis before any quote
    • The complete price, upfront
    • An honest read on repair versus replace
    Call (904) 512-0091 or book it online ↓

    HVAC Services — San Marco, FL

    From First Call to AC Repair

    Four simple steps — and no surprises at any of them.

    1 Call or Click Tell us what’s going on — phone or the form, your pick.
    2 We Sniff It Out An honest diagnosis of the real problem — not an upsell.
    3 You Approve the Price The full number upfront, before any work starts.
    4 Done Right, Tail Wags Fixed, tested and cleaned up — guaranteed.

    Residential & Commercial HVAC — San Marco, FL

    Heating and Cooling for San Marco Homes and Storefronts

    From emergency AC repair and duct cleaning to brand-new systems and mini splits — one crew across Jacksonville and Duval County.

    Not sure what you need? Call (904) 512-0091 — we’ll sniff it out.

    Heating and Cooling in San Marco, FL

    Don’t Sweat the Dog Days of Summer

    Honest techs, upfront pricing, and cool air your whole pack can agree on.

    AC Replacement & Installation in Jacksonville

    Old AC Out. New Comfort In.

    When your air conditioner is past its prime, more AC repair isn’t always the answer. A new, energy-efficient AC installation can end the breakdown cycle, cool your home evenly, and take a real bite out of summer power bills.

    Our Jacksonville team gives you the honest math on AC replacement vs. repair, sizes the new system correctly for Florida heat, and leaves the job site cleaner than we found it — just like this install.

    Old rusted air conditioner before replacement in Jacksonville
    New energy-efficient AC unit after professional installation
    Before After

    Air Conditioner Repair & Replacement

    The Lowest Ground in the City, and the Equipment Standing On It

    San Marco sits lower and closer to the water than almost anywhere else we work, and that single fact changes what matters about a system here. Four things it decides.

    A wall thermostat in a Jacksonville home, set for cooling
    Set to 78° — nine months a year
    The heightWhere the unit sits

    An outdoor unit is a machine full of electrics standing on the ground, and down here a few inches of pad height is the difference between an inconvenience and a replacement. It is the cheapest decision available and the one most often left as the builder set it.

    The waterWhat submersion really does

    Water does not politely stop at the parts that can be swapped. Compressor, contactor and control board all go at once, which is why a unit that has been under is usually a replacement rather than a repair — and why knowing that early beats finding out twice.

    The dryingWhat cannot be saved

    Bare metal duct can be cleaned and kept. Lining and insulation that have taken on water hold it, and the system then moves air across that every cycle for as long as you leave it. Telling the two apart honestly is most of the job after a bad season.

    The street levelStorefronts plan differently

    Shops and kitchens at street level carry the same risk with more equipment and less room to move it. Where the gear sits, and how quickly it can be got at, is worth settling before it matters rather than during.

    San Marco Service Area

    From the Southbank to Empire Point

    A small area, close to the water on three sides, and one where the address genuinely changes the advice. This is where the truck actually ends up.

    San Marco Square

    The middle of it. Shops, kitchens and offices at street level, which is its own conversation about where equipment sits.

    St. Nicholas

    East along Atlantic and Beach Boulevard. A mix of eras on the same street, which usually means a mix of equipment ages.

    Empire Point

    Out on the point, with water on three sides. The most exposed corner of the run and the one we watch hardest.

    Granada & Miramar

    South of the Square. Quieter streets, larger lots and longer duct runs than the San Marco average.

    The Southbank

    Offices, the riverfront and the medical district — work we cover on the commercial side rather than the residential one.

    Hendricks Avenue

    The spine running south. Most of what we do here turns off it somewhere.

    $99Refresh
    & Tune‑Up

    Limited‑time offer

    HVAC Refresh & Tune‑Up

    A full seasonal check‑over of the system you already have — so small problems stay small.

    Cannot be combined with any other offer. One per household.

    HVAC Repair & Replacement in Jacksonville

    Let’s Figure This Out Together

    No quote needed, no email, no phone number — just tell us what it’s doing and we’ll give you our honest read.

    1How old is the system?

    2What’s it doing? tick all that apply

    3How often has it needed fixing?

    The Great Dane Heating & Air mascot, wrench in hand, standing beside an outdoor AC unit

    Straight talk: If somebody tells you your system is “illegal now” because of the refrigerant rules — it isn’t. R‑410A systems can still be serviced. New equipment moved to R‑454B in 2025 and R‑410A production is stepping down, so topping off an older system gets pricier every year. That’s a reason to plan, not a reason to panic‑buy tonight.

    A Great Dane napping beside a Great Dane Heating & Air mailer A Great Dane at the Great Dane Heating & Air van Paw Partner

    Community

    The Dog Came With a Purpose

    Great Dane Heating & Air was named by people who are frankly incapable of walking past an animal, and the company was set up on the understanding that it ought to be worth something to the pet population of Duval County and not only to its customers.

    That shows up as rescue events, time given to animals still waiting at the shelter, and a Rescue of the Week put in front of everyone who follows us. It is also why we are a Paw Partner Corporate Sponsor of the Jacksonville Humane Society.

    Jacksonville Humane SocietyMeet the Jacksonville Humane Society →

    San Marco Families

    Comfort on the Low Ground

    A working air conditioner is comfort. Down here it is also equipment that needs to be sitting in the right place, because the thing most likely to end its life has nothing to do with how well it was built.

    • Vetted people in your home

      Florida state certified — licence CAC036942 — fully insured, and BBB accredited at an A+ rating. The same small crew every time, and the same people you spoke to on the phone.

    • Air that has been wet before

      Duct lining and insulation that have taken on water hold it far longer than people expect, and the system moves air across it every cycle. Filtration and humidity control help, but replacing what cannot dry is the part that actually fixes it.

    • Told straight, after weather too

      If your system came through fine you will be told it came through fine, with the readings beside it. Our work is guaranteed — that is the whole point of the name on the truck.

    A toddler standing on a Great Dane’s back to reach the thermostat in a cool, comfortable Jacksonville home
    Free estimate, honest answer. Tell us what your system is doing and we’ll tell you what it actually needs.

    Our work

    Check Out Some of Our Work

    Real installs from around Jacksonville — straight from our techs’ job sites.

    San Marco specials

    Round Up a San Marco Deal

    Helping San Marco save is one more way we give back. Mention a coupon when you call.

    The Great Dane Heating & Air truck

    Reviews

    Barking Good News From Around the Square

    ★★★★★ 4.9 out of 5 across 74 Google reviews

    Read all 74 reviews on Google →

    FAQ

    Fetch Yourself an Answer

    The questions Jacksonville asks us most — straight answers, no jargon.

    The outdoor unit went under. Is it repairable?

    Usually not in the way people hope. Once water has been through a condenser you are dealing with the compressor, the electrical components and the contactor at the same time, and the honest answer is normally replacing the outdoor half rather than a repair that will not hold. We will also tell you which parts of the system are genuinely unaffected, so you are not replacing more than you need to.

    It ran fine afterwards, then failed weeks later.

    That sequence is common and it is not a coincidence. Water leaves silt and moisture behind in places that then corrode quietly for a few weeks, so something that started fine can fail well after everything looked dry. It is why having a system looked at afterwards is worth doing even when it appears to be running.

    Why does the house smell after heavy rain?

    Look at the duct below the floor before anything else. Lining and insulation that have taken on water hold it much longer than anybody expects, and the system then pushes air across it every time it runs. Drying does not restore the lining; replacing the affected run does.

    Can the outdoor unit be raised?

    Yes, and around here it is one of the better decisions available. A taller pad or a wall bracket lifts the equipment clear of the level that causes most of the trouble, at a fraction of the cost of replacing a drowned unit. We will tell you what height actually makes sense for your address rather than guessing at it.

    Where should the air handler go in a house that has flooded before?

    Not at ground level, if the house gives you any alternative at all. An attic or a raised platform keeps the expensive half of the system out of reach of the thing most likely to destroy it. Where the layout leaves no choice, getting it up on a stand and routing the drain properly is the next best thing.

    Is there anything worth doing before the next season?

    Raising equipment and making sure the drain path is genuinely clear are both cheaper to do calmly than urgently. We are not going to tell you what the weather will do or sell you anything on that basis — only that those two jobs cost less in February than they do in September.

    After water, what actually needs replacing?

    Anything porous that got wet, and anything electrical that went under. Duct lining and insulation hold water and do not recover; bare metal duct can often be cleaned and kept. We go through it item by item and show you the difference, because the gap between those two lists is usually a great deal of money.

    What is the $99 HVAC Refresh & Tune‑Up?

    A full seasonal check‑over of the system you already have — measurements taken, the parts that genuinely foul cleaned, and a straight answer about what needs attention and what does not. On low ground it is also when we look at how the equipment sits and where water would go. Cannot be combined with any other offer, one per household.

    Is the damp in the house the air conditioner’s fault?

    Sometimes, and sometimes it is the building. A system that is oversized cools quickly, shuts off, and never runs long enough to dry the air. But this close to the water, ground moisture and a duct run that has been wet both contribute. Measuring humidity in a few rooms tells you which conversation you are actually having.

    Do you cover San Marco and St. Nicholas?

    Both, along with Empire Point, Granada, Miramar and the Southbank — all inside the normal service area at the same pricing as anywhere else we go. Great Dane is licensed in Florida as CAC036942, which you are welcome to look up before you let anybody into the house.

    Will you tell me if I do not need the work?

    Yes, and after bad weather it matters more than usual, because that is exactly when people get sold things they do not need. If your system came through it, you will be told so, with the readings that show it.

    Anything worth checking before I call?

    Three things that cost nothing. Check the breaker for the air handler and for the outdoor unit. Look at the filter, because a collapsed one starves the system and imitates a much bigger fault. And look at the base of the outdoor unit — a waterline or silt on the cabinet tells us something useful before we arrive.

    Everything we do, in your neighborhood.One crew for all of it — not a different company for each job.

    Done Right the First Time

    Honest, upfront pricing and work we stand behind 100% — that’s the Great Dane guarantee.

    The Great Dane Heating & Air van

    Serving the Jacksonville, FL area

    HVAC Service Near You

    Fast, honest HVAC service across Jacksonville, Duval County and the surrounding Northeast Florida communities.

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    Proudly serving Jacksonville & all of Duval County.

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