Central heating in a Florida home breaks in ways that look alarming and are usually simple. This guide covers what actually fails in a ducted electric heat or heat pump system, how to tell the difference before anyone quotes you a repair, and when replacement is the honest answer in 2026.
- Most Florida homes have no furnace at all: heating comes from electric heat strips or a heat pump.
- Fan runs but air stays cool? Suspect heat strips, a sequencer, or a control board first.
- Heat pumps blowing cool air in heating mode usually point to a reversing valve or defrost control.
- Systems 12 to 15 years old, or anything still on R-22, are replacement conversations, not repair ones.
- A.R. Williams Air Conditioning handles heating repair on central ducted systems across Palm Beach County and the Treasure Coast.
Why heating repair matters for Florida homeowners
Florida homeowners use heat maybe fifteen to thirty nights a year, and that is exactly why it fails. A cooling system runs almost daily, so problems show up early. The heating side sits idle from March to December, then gets asked to work on the first 45 degree night in January. Contactors stick, sequencers corrode, and heat strips that were fine last winter open up.
The second reason is that most of the heating hardware lives inside the air handler, not in a separate furnace. If your air handler is in the garage or the attic, a heating failure and a cooling failure often trace back to the same cabinet. That overlap is why air handler repair and heating repair are frequently the same visit in 2026.
Third, coastal exposure speeds all of this up. Homes east of the Intracoastal in Delray Beach, Boca Raton, and Jupiter deal with salt air that pits electrical contacts and eats at outdoor coils. A heat pump running in reverse under those conditions is working the same corroded parts the cooling cycle already stressed all summer.
“If the fan runs and the air never warms up, the problem is almost always the heat strips or the sequencer, not the compressor.”
How to diagnose and fix heating problems in a Florida home
Confirm what kind of heat you actually have
Before you search for furnace repair, find out whether you own a furnace. Gas furnaces are rare in Palm Beach, Martin, and St. Lucie counties. Most single family homes here run one of two setups.
- Straight cool with electric heat strips: an outdoor condenser plus an air handler containing resistance heating elements.
- Heat pump: the same outdoor unit runs backward in winter to pull heat inside, with heat strips as backup.
- Package unit: everything in one outdoor cabinet, common on slab homes and older builds.
- Check the model number sticker on the air handler for a "kW" rating. A 10 kW strip is the most common size in a three ton system.
- No gas line at the property means no gas furnace, full stop.
Rule out the thermostat and the breaker
Heat strips draw serious current. A 10 kW strip pulls roughly 42 amps at 240 volts, which is why it sits on its own breaker separate from the cooling circuit. Homeowners often assume the heat is dead when only that one breaker is off.
- Set the thermostat to Heat and raise the setpoint at least 5 degrees above room temperature.
- Check the panel for a second air handler breaker, often a 60 amp double pole.
- Look for a tripped float switch that killed the whole system after a drain line backup.
- Replace a filter that has been in place longer than 90 days.
- If the breaker trips again the moment heat calls, stop and get it diagnosed. Repeated tripping is covered in our guide to an AC unit that keeps tripping the breaker.
Read what the air coming out of the vents is telling you
Supply air temperature is the fastest diagnostic in the house. Hold a thermometer at a supply register five minutes after the heat starts.
- Air at room temperature with the blower running: heat strips, sequencer, or control board.
- Air slightly cooler than the room on a heat pump: reversing valve stuck in cooling mode.
- Warm air for two minutes, then cool: a heating element cycling out on its limit switch.
- Warm air only in some rooms: a duct problem, not a heating component.
- A brief burnt dust smell on the first run of the season is normal and should clear within ten minutes.
Handle the heat pump specific failures
Heat pumps add parts that straight cool systems do not have. In South Florida the reversing valve and its solenoid see very little use, which is precisely why they seize.
- A reversing valve that will not shift leaves you with air conditioning in January.
- A failed defrost board makes the outdoor coil ice over on a damp 40 degree night.
- Auxiliary heat that runs constantly usually means the heat pump side has quit and the strips are carrying the whole load.
- Watch the electric bill. A month where usage jumps with no lifestyle change often means strips ran nonstop.
Bring in a technician for anything past the panel
Everything above is homeowner territory. Sequencers, heating elements, limit switches, contactors, and reversing valves are 240 volt components inside a live cabinet, and they are not guesswork parts. This is where A.R. Williams Air Conditioning takes over: our technicians test the elements individually, check amp draw against the nameplate rating, and show you what failed before quoting anything.
- You get flat rate pricing quoted before work starts, so the number does not move.
- The technician explains what was found and lays out the options rather than pushing one.
- Same day service when we have it, and we are open seven days a week, 7AM to 10PM.
- Long term repairs over quick patches, especially on coastal systems where a corroded contactor will just fail again.
Decide repair versus replacement with real numbers
Age decides most of these calls. A 2019 heat pump with a bad sequencer is a straightforward repair. A 2011 system on R-22 with a seized reversing valve is not, because R-22 supply has been drying up for years and the rest of that system is on the same clock.
- Under 10 years: repair, almost always.
- 10 to 15 years with one failed major component: run the numbers both ways.
- Over 15 years, or any R-22 system: replacement is usually the better investment.
- Two failures in one season on the same unit: replacement.
- Read our breakdown of AC repair or replacement before you commit either way.
Heating repair options compared
| Option | Best for | Key limitation |
|---|---|---|
| Heat strip and sequencer replacement | Air handlers where the blower runs but air stays cool | Does nothing if the fault is the control board or thermostat wiring |
| Control board or relay replacement | Systems that click and hum without producing heat | Boards for pre 2012 models can be slow to source |
| Reversing valve or defrost control repair | Heat pumps blowing cool air in heating mode | On systems past 12 years, the repair rarely returns its value |
| Duct repair and sealing | Homes where two or three rooms never warm up | Fixes distribution only, not a failed heating component |
| Full system replacement, matched heat pump | Systems 12 to 15 years old, or anything on R-22 | Requires a county permit and a final inspection |
Common mistakes Florida homeowners make with heat
Waiting until the first cold front to test it. The last week of December is when every homeowner in Palm Beach County discovers the heat is out at the same time. Run the heat for fifteen minutes in October instead.
Assuming a burning smell means fire. Dust settles on heating elements over nine idle months. First run of the season, it burns off. A smell that persists past ten minutes, or one that is sharp and electrical rather than dusty, is a different story and needs a technician.
Letting snowbird homes sit with the system fully off. A house in Wellington or Palm Beach Gardens that sits empty from April to November comes back to a system that has not cycled in seven months. Stuck contactors and seized blower motors are the usual result.
Treating uneven heat as a heating problem. Older housing stock across Lake Worth Beach and Greenacres often has undersized returns and leaky ducts. If the master bedroom is cold in winter and hot in August, the ductwork is the suspect, not the heat strips.
Approving a compressor quote for a heating complaint. In a straight cool system with electric heat, the compressor plays no part in heating at all. If someone quotes compressor work because your heat is out, get a second opinion.
FAQ
Why does my Florida home blow cold air when the heat is on?
On a heat pump, cold air in heating mode usually means the reversing valve did not shift. On a straight cool system with electric heat, it means the heat strips or the sequencer that energizes them has failed.
Do I have a furnace or a heat pump?
Almost no South Florida home has a gas furnace. Check the air handler label for a kW heating rating, which indicates electric heat strips, and check whether the outdoor unit runs during a heating call, which indicates a heat pump.
Is a burning smell from the heat normal?
A faint dusty smell on the first heating run of the season is normal and clears in about ten minutes. A sharp electrical or plastic smell is not, and the system should be shut off and inspected.
Can electric heat strips trip the breaker?
Yes. A 10 kW strip draws roughly 42 amps at 240 volts, so a failing element, a weak breaker, or a loose lug will trip the circuit. Repeated tripping needs diagnosis rather than repeated resets.
Does heating repair require a permit in Florida?
Component level repairs such as heat strips, sequencers, or control boards generally do not require a permit. Replacing the full system does, and Palm Beach, Martin, and St. Lucie counties each run their own permitting and inspection process.
Should I repair or replace a 14-year-old heat pump?
If the failed part is a major component like the reversing valve or compressor, replacement is usually the better investment at 14 years. A minor electrical part on an otherwise healthy system is worth repairing.
Why did my electric bill spike in a cold month?
Auxiliary heat strips consume far more power than the heat pump itself. If the heat pump side fails, the strips carry the entire load and the bill jumps even though the house feels normal.
How often should heating be checked in a home that sits empty part of the year?
Once a year before the cool season, plus a startup check when you return. Systems that sit unused for six or seven months develop stuck contactors and corroded contacts more often than year round systems.
One last thing
The single most common heating repair we see in 2026 is not a dramatic failure. It is one open heat strip out of two or three, which means the system still makes heat, just not enough of it. The house drifts to 68 degrees and never reaches the setpoint, so the homeowner blames the thermostat and lives with it for two winters. Have the amp draw checked against the nameplate rating. That test takes a technician about five minutes and settles the question.
Related guides
- How to troubleshoot an AC that won't turn on
- AC repair for older homes in South Florida
- Attic air handler repair for South Florida homes
