The half of your system that sits unused for nine months, then gets discovered on the first genuinely cold night — the same night everybody else finds theirs. We find what actually failed and tell you honestly whether it can wait.
Get a free estimateTell us what it’s doing — we’ll come back fast.
Heating repair in Jacksonville
The System Nobody Tests Until the First Cold Night
Heating is the half of your system that sits unused for most of the year. It runs a handful of weeks here, which means a fault that developed in June is not discovered until the first genuinely cold night in November — the same night everybody else in Duval County finds theirs. Most of what we fix is not dramatic: a strip heater that has failed open, a sequencer that will not close, a reversing valve stuck in cooling, a heat pump defrost board that quit. The system feels fine right up until the day you need it.
Great Dane Heating & Air has kept Jacksonville and Duval County comfortable for more than twenty years. We are a family company — the people who answer the phone are the people who show up — with upfront pricing, comfort techs who treat your home like their own, and a soft spot for shelter dogs. Every job we finish gives back to the Jacksonville Humane Society.
Nine months of sitting still is hard on a heating system. Tap whichever one sounds like your house.
A heat pump moves heat rather than making it, so its air is genuinely cooler than a furnace’s — that part is normal. Barely warm at all usually means the strips are not coming on, or the outdoor unit is not reversing.
Cooling works, heat does nothing. On a heat pump that points at the reversing valve or its control; on a system with strips it usually points at a sequencer or the strips themselves.
Dust that settled on the strips all summer burning off is normal and fades within a few minutes. A sharp electrical or plastic smell, or one that does not fade, is not — shut it off.
A heat pump frosting up in cold damp weather is normal, and it should defrost itself on a cycle. Ice that never clears, or that builds into a solid block, means the defrost cycle is not working.
Usually the strips carrying more of the load than they should — either the heat pump is not doing its share, or the strips are energised when they have no reason to be.
A heat pump running a long cycle in cold weather is doing its job. Running non‑stop and still losing ground is different, and on the coldest mornings of the year it is worth knowing which one you are looking at.
Cannot be combined with any other offer. One per household.
Our Furnace Repair Process
How a Heating Repair Actually Goes
No mystery, no pressure, and no work done before you’ve agreed to it.
01We find out what is actually calling for heat
Whether the thermostat is asking for the heat pump, the strips, or both — and whether the equipment is doing what it was told. That answer changes everything that follows.
02We check the electrical side properly
Strip heaters, sequencers, contactors and the connections around them. Heat draws far more current than cooling does, and this is where most winter failures actually live.
03You get the number before we start
The failed part, what it costs, and whether it is worth doing against the age of the system. No work happens before you have agreed to it.
04We test it in heat before we leave
Not just that it starts — that it produces a proper temperature rise and hands off between the heat pump and the strips the way it should.
Before the first cold night
Nine Months Off Is Hard on a Heating System
What actually goes wrong sitting idle
None of it is dramatic, and none of it announces itself in August.
A heat strip that failed openIt reads fine until it is asked to carry the house, and then it simply is not there.
A sequencer that will not closeThe call for heat arrives and nothing downstream of it wakes up.
A reversing valve stuck in coolingThe heat pump runs happily and blows cold, which is the one you notice at 2am.
A defrost board that quitShows up as a block of ice on the outdoor unit, not as an error message.
Jacksonville’s average overnight low falls from 74 degrees in September to 56 in November. NOAA 1991–2020 climate normals.
Heating season here is short. Sometimes the honest answer on a November repair is that the part can wait, or that the sensible time to deal with it is when we are already there for the cooling side. Selling you a winter emergency in Jacksonville is easy, and it is exactly the thing we would rather not do.
What you might hear
“Your heat exchanger is cracked.”A serious finding on a gas furnace — and most Jacksonville homes do not have one. Ask what you actually have.
“You need a new system before winter.”Said in November, about a system that cooled your house fine in August.
“We can get to you first thing if you decide today.”Urgency is the oldest close in this trade.
What we’ll tell you
“Here is the part that failed.”And the reading that told us, before we replaced anything.
“This one can wait.”Some winter repairs genuinely can. We will tell you when yours is one of them.
“You have a heat pump, not a furnace.”Which rules out a whole category of things you may have been told.
A short mild season changes what breaks and when you find out. Four reasons — and where each one lives in your house.
78°Set to 78° — nine months a year
Nine monthsSitting still, not wearing out
Your heating runs a handful of weeks a year. Contactors sit, connections oxidise, and a fault that developed in the spring waits until the first cold night to introduce itself.
The stripsWhere the current goes
Electric resistance heat draws far more current than cooling does. That load lands on sequencers, contactors and lugs that spend most of the year idle, and it finds every weak connection.
Damp coldFrost and defrost
Jacksonville cold comes wet. A heat pump frosts up in exactly those conditions and has to defrost itself on a cycle — and a defrost board that has quit shows up as a block of ice, not as an error message.
The atticHeat lost on the way
Nearly every system here runs its ducts through an unconditioned attic. A heat pump delivers warm air rather than hot to begin with, so what leaks away on the trip to the register is a real share of what you paid for — and a gap on the return side pulls cold attic air straight in.
Whatever you’re running
Condensers, Mini‑Splits, Heat Pumps — We Work On All of It
Straight-cool split systems, ductless mini‑splits, heat pumps, package units. If it cools a Jacksonville home, we’ve had our hands inside one.
A working air conditioner is comfort. A system looked after properly is something closer to peace of mind — especially in a Jacksonville August, and especially with small people in the house.
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, not a rotating list of subcontractors.
The air they breathe all day
Florida humidity does not just make a house uncomfortable — it feeds what grows in it. Filtration, purification and humidity control keep the air in your rooms clean as well as cold.
Fixed right the first time
We show you the failed part, quote the whole number before we start, then test the system and clean up behind us. Our work is guaranteed — that is the whole point of the name on the truck.
Free estimate, honest answer.Tell us what your system is doing and we’ll tell you what it actually needs.
Paul came out and replaced our blower motor and saved the day. He fielded my call on Sunday evening, then did the service Monday afternoon. Friendly, efficient, and professional.
After years of feeling vulnerable to dishonest HVAC companies, a neighbor put me in touch. He quickly earned my trust — quick to return calls, reasonable rates, and he’s never tried to sell me things I don’t need.
We’ve used him for everything from small tweaks to replacing our entire unit. Quick, reliable, honest, and clean — and he beat the prices of every competitor. Yes, we priced out seven.
Fast and efficient, unbelievably affordable pricing. He quickly figures out the problem and explains it in a way anyone can understand. You automatically feel like you can trust him.
Our A/C went down and the team showed up Monday morning first thing. We had cool air flowing in no time. The crew was fast, clean, and finished under time.
Mike and the team were very professional, friendly, and knowledgeable. The price was not unreasonable. So happy we found this company — we know we will be taken care of in the years to come.
Just had Great Dane install a new A/C in my home. Mike came to my home, saw what I had, and I told him what I wanted installed. There was absolutely no sales pressure.
Mike came out and gave an estimate with no fluff, which is what I like. He was honest and professional. The team that installed the unit worked well together and the work performed was stellar!
My experience was beyond my expectations. They did an amazing job replacing my antique air conditioner! Mike gave me a great quote and DJ and his son completed this challenging job amazingly well.
Our outdated A/C system went down for good and I had called multiple other companies with little to no response. I called Great Dane and Mike was at my house in less than 15 minutes.
So glad I went with Great Dane to service my a/c. I highly recommend Quentin, who serviced the unit. He is extremely knowledgeable, highly competent, and up front about potential issues.
I’d been without A/C for quite some time. It was amazing — the care and concern that Mike (and MJ & Brandon) had about my situation. I know I chose the right company.
Straight answers, no jargon — including the ones that cost us money to answer honestly.
Do I have a heat pump or a furnace?+
Most Jacksonville homes have a heat pump, which is the same outdoor unit that cools you in summer running in reverse, with electric strips inside as backup. If your outdoor unit runs in winter, you have a heat pump. If there is a gas line to the indoor equipment and a flue, you have a furnace. It matters, because a whole category of things people get told about furnaces cannot happen on a heat pump.
Why is the air from my vents not hot?+
Because a heat pump moves heat rather than burning something to make it, its supply air is genuinely cooler than a furnace’s — warm rather than hot. That is normal and not a fault. What is not normal is air that is barely warmer than the room, which usually means the strips are not engaging or the outdoor unit is not reversing.
Why does my outdoor unit ice up in winter?+
A heat pump pulls heat out of outdoor air, which drops the coil below freezing and condenses moisture onto it. Frost is expected in cold damp weather and the system is designed to melt it off on a defrost cycle. Ice that never clears, or that builds up into a solid block around the coil, means the defrost cycle is not doing its job — and running it like that is hard on the compressor.
It smells like burning when the heat first comes on. Should I worry?+
The first run of the season usually smells for a few minutes as dust that settled on the strip heaters all summer burns off. That fades and is nothing. A sharp electrical smell, a plastic smell, or any smell that does not fade is different — shut it off at the thermostat and call.
Can a heating repair wait until spring?+
Sometimes, honestly. Heating season here is short, and there are failures that leave you with working backup heat and no safety issue — those can reasonably wait, and often the sensible time to deal with them is when we are already there for the cooling side. There are also failures that cannot wait, and we will tell you which one you have rather than treating every November call as an emergency.
Is it worth repairing heat on an old system?+
It depends on what failed and on what the cooling side is doing, because it is one system. A cheap strip or sequencer on an otherwise healthy system is worth doing. The same repair on equipment that is already struggling every summer is money spent on a system you will be replacing anyway — and we would rather say that in November than take the work.
One call covers the rest of the house.This page is one job. These are the others.
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