AC running but not cooling
AC running but not cooling in Winter Springs, Florida
When the system runs continuously but the house never gets cool, the usual causes are a dirty condenser coil, a low refrigerant charge, duct leakage into a hot attic, or a system that is simply undersized for the load it now faces. It is a capacity problem, not a power problem, and in 1980s Winter Springs housing the ductwork is the first suspect.
Diagnosis
What is most likely wrong
| # | Cause | How common | What it looks like |
|---|---|---|---|
| 1 | Duct leakage into the attic | Very common | One or two rooms never keep up; supply air is cool at the register but weak; the attic is 130 degrees and the return is pulling from it. |
| 2 | Dirty condenser coil | Very common | Unit runs hot, discharge air off the top is scorching, cooling fades on the worst afternoons. |
| 3 | Low refrigerant charge | Common | Cools, but never reaches set point. Ice may form on the suction line. |
| 4 | Blocked filter or dirty evaporator coil | Common | Low airflow at every register, not just one. |
| 5 | Undersized or wrongly sized system | Common | Never a problem until a west-facing addition, a removed tree or a new set of windows. |
| 6 | Failing compressor | Less common | Runs, draws high current, moves little heat. The last stage before it stops. |
| 7 | Thermostat sensing a wrong location | Less common | Stat on an interior wall near a supply register satisfies early; the far rooms never do. |
Before you call
What you can safely check yourself
- Hold a hand at a supply register: cool but weak points to airflow; barely cool but strong points to charge or the condenser.
- Look at the condenser coil fins from the inside with the power off at the disconnect. If you cannot see daylight through them, they are the problem.
- Check the attic hatch on a hot afternoon. If the attic is roaring hot and a duct run has fallen off a boot, you have found it.
- The filter and the return grille — a return partly blocked by furniture is a capacity loss you can fix in a minute.
- Note what changed: a new roof, removed shade, a converted garage. Load goes up; the system did not.
Where the licensed line is
Refrigerant, capacitors and the inside of an electrical panel are not homeowner jobs. A run capacitor holds a lethal charge after the disconnect is pulled. Refrigerant handling requires EPA Section 608 certification. And in Florida the work itself is regulated: an air-conditioning contractor licensed under Chapter 489 may replace, disconnect and reconnect the power wiring at the dedicated disconnect, and repair or replace breakers and fuses on dedicated HVAC circuits — s. 489.105(3). Verify any Florida contractor's licence at the DBPR licensee search before work begins.
In Winter Springs
Why this happens in this housing stock
Attic flex duct from the 1970s and 80s is the most common thing still found original in a Winter Springs house. The condenser has been replaced three times; the trunk has not, and it leaks at the boots and the plenum. In a vented attic that is conditioned air you paid for going into a space at 130 degrees, which is why a leakage test is the first thing to do in the 51.2% of the city built before 1990. What sealing and replacement cost, and the Duke $450 rebate.
The undersizing case is the Tuscawilla one: the 1980s units 14A and 14B have medians of 2,582 and 2,686 sq ft, often on one system that was marginal when new. Why a load calculation, not a rule of thumb.
Source: Seminole County Property Appraiser CAMA extract, files dated 5 September 2026. Improved residential parcels (single-family, townhome and condominium; DOR codes 01xx and 04xx) in tax districts W1 and W2.
Cost
What the fix typically costs
| Job | Researched range | What drives it |
|---|---|---|
| Diagnostic visit | $70–$200 | Usually credited. |
| Condenser coil cleaning | $80–$250 | Part of any service visit; priced here as a call. |
| Refrigerant leak repair | $200–$1,500+ | Finding the leak is most of the cost. |
| Duct sealing | $500–$2,500 | After a leakage test says the runs are sound. |
| Full duct replacement | $2,500–$8,000 | When they are not. |
| Full system replacement, 3 ton | $6,000–$9,500 | If it was never the right size. |
Researched ranges from HomeGuide, HVAC Calculator Hub and This Old House (national, updated 16 March 2026), checked September 2026. Not our prices.
Read this before you use any number on this page
These are researched market ranges, not our prices and not a quote. The dollar figures come from published third-party cost guides — named and linked at the foot of the page — plus one figure that is not a range at all: the City of Winter Springs’ own published mechanical permit fee. They are here so you can tell whether a quote you have been handed is in the ordinary range for this work. No two houses in Winter Springs cost the same to do, and we do not quote a job before we have seen it.
Problems
Not getting anywhere?
Tell us the symptom, the build year of the house and roughly how old the equipment is. That usually narrows it to two candidates before anyone drives out.
Sources
Where the facts on this page come from
Every figure above is either a primary-source document or a named third-party cost guide, and all of it was checked in September 2026. Fee schedules, rebate amounts and market prices change without notice — if you are about to spend money on one of these numbers, open the source and check it.
- This Old House, air conditioner repair cost guide (national, updated 16 March 2026)
- HomeGuide, HVAC repair cost guide
- Smart Home Air & Heat, new AC unit cost in Orlando (a local contractor’s own guide — read as one operator’s view)
- Duke Energy Florida, Home Energy Improvement HVAC replacement
- Fla. Stat. s. 489.105(3) — air-conditioning contractor classes and scope
- Florida DBPR licensee search
- Seminole County Property Appraiser