A twelve-year-old heat pump in Mandarin has two roads left, and both start with a visit
Most Jacksonville houses run on a heat pump, and most of those are now old enough to make the owner choose. Here is how that choice gets made.
Twelve years in
Picture the heat pump behind a brick-front house in Mandarin, installed the year the owner’s daughter started kindergarten. She is in high school now. The system has cooled through twelve Jacksonville summers of 90-degree afternoons and dew points in the 70s, heated through a dozen winters of frosty mornings, and survived at least two tropical systems and every lightning season in between.
At twelve, a heat pump in this climate is at a fork. One road is a repair that buys three to five more years. The other is a replacement that resets the clock and the JEA bill. Which road is right depends entirely on what is actually wrong, and the only way to know is to measure.
The problem, as it usually arrives
Heat pump trouble in Jacksonville announces itself in one of five ways:
- The house will not get below 77 on a hot afternoon, though the system runs all day.
- The air at the registers in January is room temperature, and the JEA bill doubled.
- The outdoor unit is iced over, or steams and drips constantly.
- The breaker trips, usually right after an afternoon storm.
- A new sound: a rattle at the condenser, a hum with no fan, a screech at the air handler.
Each one points somewhere different, which is why the phone call is the start of the diagnosis and not the end of it.
What the visit measures
A Cook’s heat pump visit measures before it concludes. The technician records refrigerant pressures and temperatures in both modes, amp draw on the compressor and both motors, capacitor values, the condition of the contactor and the defrost board, the thermostat’s staging and the strip heat circuit, airflow and static pressure through the ducts, the condensate drain and float switch, and the physical state of the coils: pollen on the outdoor coil in spring, salt damage on anything within a few miles of the ocean, and corrosion on units that sat in floodwater in Riverside, San Marco or Ortega.
What twelve-year-old heat pumps are usually hiding
In a twelve-year-old Jacksonville heat pump, the findings cluster:
| Symptom | Most common finding here | Scale |
|---|---|---|
| Runs all day, never catches up | Low charge from a slow coil leak, or a pollen-choked outdoor coil | Small to medium, unless the coil must be replaced |
| Strips carrying the house in winter | Defrost board, reversing valve solenoid, or thermostat staging | Small to medium |
| Iced outdoor unit | Failed defrost sensor or low charge | Small to medium |
| Trips after storms | Surge-damaged board, capacitor or contactor | Small to medium; sometimes several parts |
| Hum, no fan | Capacitor or condenser fan motor | Small |
| Screech or grind indoors | Blower motor bearings | Medium |
| Loud start, high amps | Compressor on its way out | Large; this is the fork |
What the repair price depends on
The repair price is quoted after the diagnosis and before the work. What moves it is the part, whether refrigerant is involved, how reachable the air handler is, and whether the failure took other components with it. A capacitor in a Baymeadows garage is the low end. A reversing valve or a compressor in an attic unit above a Murray Hill bungalow with no decking is the high end. The time of day moves nothing: Cook’s charges the same on a Sunday night as on a weekday morning.
Agreement customers see member pricing on repairs; ask for the specifics when you enroll. [[CONFIRM WITH JERRY]]
When replacement is the better road
We would rather repair a twelve-year-old heat pump than sell a new one, and most visits end as repairs. The exceptions are specific:
- The compressor has failed and the system is past about twelve years.
- The coil is leaking on an R-22 system, which still describes a good share of the units in Arlington and Westside ranches.
- The repair quote is more than roughly a third of a new system.
- The unit has been under floodwater and the corrosion is general, not local.
- The ductwork is wrong for the house and will have to be redone anyway.
In those cases you get a replacement quote beside the repair quote. New heat pumps meeting JEA’s Tier 1 thresholds of 16 SEER2, 11.0 EER2 and 8.0 HSPF2 have qualified for a $200 Heating & Cooling rebate applied on the contractor’s invoice; the 2026 cycle closed on October 10, 2026; ask whether the next one has opened before you order. [[CONFIRM WITH JERRY]] Clay Electric members in the Baker County portions have had a separate rebate. Financing with low monthly payments is available on new high-efficiency systems and quoted in writing, and the federal 25C credit ended with 2025.
Service for every heat pump in the three counties
Cook’s installs Lennox and repairs and maintains Lennox, Carrier, Bryant, Trane and every other brand of heat pump, including the package units on manufactured homes in Baker and Nassau and the ductless mini-splits in Jacksonville Beach and Fernandina condos. Jacksonville is about 74 minutes up I-95 from the Palm Coast headquarters at 37 Fairmont Lane, the routes are built daily, and the phone is answered around the clock.
Heat pump questions from Jacksonville homeowners
On a 26-degree morning will the heat pump keep up, or does it just run the strips?
A correctly sized, well-maintained heat pump carries most of the load down into the 30s and leans on the strips during the three or so hard freezes Jacksonville sees a winter. If the strips run on every 45-degree morning, something is wrong: thermostat staging, a defrost issue, low charge or a tired compressor. That is a service call, not a design flaw.
Should the fan switch sit on AUTO or ON in this humidity?
AUTO, in Jacksonville, almost always. On ON, the blower keeps running between cooling cycles and re-evaporates the water sitting on the coil, pushing humidity back into the house. With dew points in the 70s all summer, that is the wrong trade.
Why is there frost on the outdoor unit in January, and is that a defect?
Light frost that clears within an hour is the normal product of pulling heat out of damp 40-degree air; the defrost cycle handles it. A unit encased in ice at midday, or one that steams and drips every few minutes, has a defrost control or sensor problem.
Is it normal for a heat pump to run constantly on a hot afternoon?
On a 93-degree August day with a 73-degree dew point, long run times are expected and even desirable, because that is when the system is pulling water out of the air. Constant running on an 85-degree day, or running without ever reaching the setpoint, is a sign of low charge, a dirty coil or a system that is undersized for the house.
Other services in Jacksonville
- A/C ServicesRepair, tune-ups, replacements and duct work for Duval, Nassau and Baker, from one phone number.
- A/C RepairDiagnosed, quoted, then fixed. Nights and weekends at the daytime price, every brand on the street.
- A/C MaintenanceTwo visits a year, one before the heat and one after it, built around Jacksonville's pollen, storms and salt.
- A/C InstallationA decision tree for repair versus replace, then a load-calculated install with the JEA rebate handled on the invoice.
- ThermostatsSmart, programmable or plain. Matched to the wiring your house actually has, with the JEA rebate in mind.
- GeothermalGround-loop heat pumps for large Jacksonville lots, Nassau and Baker acreage, and commercial sites with parking to drill under.
- Heating ServicesHeat pumps, gas furnaces, electric strips and ductless units, serviced for a winter of fourteen freezes and three hard ones.
- Heat Pump RepairCapacitors, boards, reversing valves, defrost controls and compressors, any brand, any hour, same price.
- Heat Pump MaintenanceSpring and fall visits that test both modes, because a heat pump that passed August can still fail the first freeze.
- Heat Pump InstallationLoad-calculated Lennox heat pumps, set above the flood line and behind a surge protector, with the JEA rebate on the invoice.
- Furnace RepairIgniters, flame sensors, inducers, sequencers and heat exchangers, diagnosed with a meter and a camera, not a guess.
- Furnace MaintenanceCombustion analysis, camera inspection and a cleaned flame sensor before the first freeze, for gas, propane and electric furnaces.
- Furnace InstallationGas and propane furnaces, dual-fuel pairings and the honest case for skipping the furnace altogether.
- Air QualityHumidity, pollen, dust and musty air, traced to the way each Jacksonville house was built and fixed accordingly.
- Indoor Air QualityMeasured assessments for houses and businesses, then filtration, dehumidification, ventilation and duct sealing matched to the readings.
- Duct CleaningA look inside first, then cleaning, sealing or replacement, whichever the ducts actually need.
- CommercialRooftop units, split systems and three-phase equipment for offices, restaurants, shops and medical suites across Duval, Nassau and Baker.
Heat pump on the fence?
One visit gives you readings, a repair price and, if it is warranted, a replacement price beside it.