Problems · Running but not cooling

AC running but not cooling in Lake Mary, Florida

When the system runs constantly but the house never gets cool, the usual causes are a dirty condenser coil, a slow refrigerant leak, duct leakage into a hot attic, or a system that cannot keep up with the load a Lake Mary pool house actually carries. It is a capacity problem, not a power problem.

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What is most likely wrong

Dirty or blocked condenser coil Very common
Outdoor unit running hard; air off the top of it barely warm; long run times.
Duct leakage or crushed flex in the attic Common
One or two rooms far worse than the rest; the system never satisfies the thermostat.
Low refrigerant charge from a slow leak Common
Gradual decline over weeks; ice at the evaporator or suction line in bad cases.
Dirty evaporator coil Common
Weak airflow at every vent even with a fresh filter.
Undersized for a pool-heavy load Lake Mary-specific
Constant runtime that was never a repair problem — the equipment can be correctly matched to the house on paper and still not keep up against a wide glass span onto the lanai.

What you can safely check yourself

The condenser coil from the outside: rinse packed grass clippings, pollen and pool-cage debris from the inside out, power off at the disconnect first.
The filter, even if it was changed recently — a humid attic loads one faster than the interval on the box.
Vent-to-vent airflow, room by room. One dramatically worse room points at a duct problem, not the equipment.
Whether the system is icing at the indoor coil or suction line — if so, turn it off and let it thaw before calling.

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, and refrigerant handling requires EPA Section 608 certification under 40 CFR Part 82 subpart F.

In Florida, an air-conditioning contractor licensed under Chapter 489 may replace, disconnect and reconnect the power wiring at the dedicated disconnect — s. 489.105(3) — which is exactly why that scope exists: it is not general household electrical work. Verify any Florida air-conditioning contractor’s licence at myfloridalicense.com.

Why this shows up in Lake Mary and Heathrow

44.5% of improved residential parcels in the City of Lake Mary tax district have a pool — the highest share of the seven Seminole County cities measured — and a pool house here is usually the house with the wide sliding-glass span onto the lanai. Glass is load, and a system that runs constantly in a pool house is sometimes working exactly as hard as it was sized to, just not hard enough for the house it is cooling.

Before assuming the equipment itself is undersized, rule out the two faults that mimic it: a dirty condenser coil restricts heat rejection outside, and attic duct leakage dumps conditioned air into a space that runs well over 120°F in summer. Both make a correctly sized system behave like an undersized one. More on pool homes and humidity ›

What the fix typically costs

Researched Central Florida ranges — not our prices
Item	Researched range	What drives it
Refrigerant leak search and repair	$400–$1,600	Orlando; a recharge alone runs about 75 minutes, a leak search adds 2–4 hours on top of it.
Duct sealing	$500–$2,500	Orlando; individual section replacement runs $200–$800.
Evaporator coil replacement	$1,500–$2,500	Orlando market range, parts and labour.
Compressor replacement	$1,200–$2,800	Orlando market range — weigh it against a full changeout before authorising it.

Researched Central Florida ranges gathered 12 September 2026 for research/pricing.json: Orlando-metro contractor-published prices corroborated against a third-party Orlando cost guide, with any aggregator figure labelled as such. These are market ranges, not our prices, and not a quote.

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Sources for this page

Researched 6 September 2026. Fees, rebate amounts and code minimums change — check the issuing authority before you rely on a figure.