Running but not cooling

AC running but not cooling in Oviedo, Florida

When the system runs continuously but the house never gets cool, the usual causes are a condenser coil packed with oak litter and pollen, low refrigerant, duct leakage into a hot attic, or equipment that no longer matches the load. In Oviedo it is a capacity problem, not a power problem, and the outdoor coil is the first place to look.

Diagnosis

What is most likely wrong

Likely causes, ordered by how often they turn out to be the answer
#	Cause	How common	What it looks like
1	Dirty or blocked condenser coil	Very common	Outdoor unit running hard, air off the top of it barely warm, long run times.
2	Duct leakage or crushed flex in the attic	Very common	One or two rooms far worse than the rest; the system never satisfies.
3	Low refrigerant charge from a leak	Common	Gradual decline over weeks. Ice at the evaporator in bad cases.
4	Dirty evaporator coil	Common	Weak airflow at every vent even with a new filter.
5	Failing capacitor or a compressor running weak	Common	Long cycles, a high bill, some cooling but never enough.
6	Undersized or wrongly matched equipment	Less common	Never keeps up on the hottest afternoons but fine in April. Often a system replaced without a load calculation.
7	Strip heat energised alongside cooling	Less common	A miswired changeout. Rare, expensive, and it feels exactly like this.

Before you call

What you can safely check yourself

Filter first, always.
Look at the outdoor coil: if you cannot see daylight through the fins, it is blocked. Rinse from the inside out with the power off at the disconnect.
Feel the air off the top of the condenser while it runs: it should be noticeably warm. Cool air means the compressor is not doing much.
Walk the attic if you safely can: crushed, disconnected or sweating flex duct is visible without tools.
Note the supply temperature at a vent against room temperature: a healthy system pulls roughly 16–22°F below.

Where the licensed line is

Refrigerant, capacitors and the inside of an electrical panel are not homeowner jobs. A run capacitor holds a lethal voltage 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 disconnects, breakers and fuses on dedicated HVAC circuits — s. 489.105(3). Verify any Florida contractor’s licence, including ours, at DBPR Verify a Licensee.

In Oviedo

Why this happens in this housing stock

The condenser coil is the Oviedo cause. The City permits removal of any canopy tree and Live Oak Reserve’s development agreement requires three hardwoods per lot, so a condenser under a live oak is the normal condition here. Leaf litter, catkins and pollen pack the fins from the inside, head pressure climbs, and the system runs hard while rejecting less heat. It is the first thing to check and the cheapest thing to fix.

The second Oviedo cause is the attic. The median home was built in 1995; in Alafaya Woods and Twin Rivers the duct trunk is often original to 1985–96 and sits in a vented attic that reaches 130°F. Duct leakage there is cooling paid for and thrown away. A modern variable-speed air handler on those ducts makes it worse, not better, which is why a duct allowance belongs on an Oviedo changeout quote.

Housing stock: Seminole County Property Appraiser CAMA extract, Parcels.csv dated 5 September 2026. Median build year 1995; 25.0% of parcels built 1970–89; 39.4% with a pool.

Cost

What the fix typically costs

Researched repair ranges for this symptom, 2026
Job	Researched range	Notes
Diagnostic visit, national	$75–$150	This Old House 2026. A competing Oviedo contractor publishes $89, waived with a completed repair.
Refrigerant leak repair	$200–$1,500+	Finding the leak is most of the cost; weigh it against the R-410A phase-down.
Evaporator coil	$700–$2,500+	On a system past twelve years, usually the point replacement gets costed.
Duct repairs or modifications	$500–$1,500	Florida cost guide; the duct allowance on an Oviedo changeout.
Capacitor replacement	$150–$400	Angi puts the average at about $250 fitted.

Read this before you use any number on this page. Every figure here is a researched third-party market range with its source and capture date named beside it. None of them are a contractor’s price and none of them are a quote. They are here so you can sanity-check a quote you have already been given.

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.

Call (321) 415-3018 Send the address and build year

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