AC not turning on
AC not turning on in Longwood, Florida
A thermostat with no display, a tripped breaker or a blown low-voltage fuse account for most no-power calls. After that it is the same capacitor and contactor failures that show up across every other symptom on this site — Florida's heat and lightning-storm frequency make them the most common single AC repair in the state.
Diagnosis
What is most likely wrong
| # | Cause | How common | What it looks like |
|---|---|---|---|
| 1 | Dead thermostat batteries or a tripped breaker | Very common | Blank thermostat screen, or a breaker visibly tripped at the panel. |
| 2 | Outdoor disconnect pulled or breaker off | Very common | Central Florida's summer lightning frequency makes a storm-tripped breaker a routine, not a rare, cause here. |
| 3 | Blown low-voltage fuse or tripped condensate float switch | Common | Thermostat is dead but the panel breaker is fine; often the same float switch behind a not-cooling call. |
| 4 | Failed contactor or capacitor | Common | Thermostat calls for cooling, nothing outside responds. |
| 5 | Failed control board or transformer | Less common | Thermostat display stays blank even with fresh batteries and good breakers. |
| 6 | Failed compressor start components | Less common | A single hard hum, then the breaker trips on every start attempt. |
Before you call
What you can safely check yourself
- Thermostat batteries, if it takes any, and whether the screen lights up at all.
- Both breakers at the panel — air handler and condenser are usually separate.
- The outdoor disconnect pull-out is fully seated.
- Look (do not open the panel) for an obviously blown low-voltage fuse or a reset button on the air handler's control board.
- If the air handler is in the attic, check whether the condensate pan is full — that trips the same safety switch that kills power to the whole system.
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, and refrigerant handling requires EPA Section 608 certification. In Florida the work itself is regulated: an air conditioning contractor licensed under §489.105(3) may replace, disconnect and reconnect the power wiring at the dedicated disconnect, and repair or replace disconnects, breakers and fuses on dedicated HVAC circuits — that scope exists because this is not general-purpose electrical work.
Verify any Florida contractor’s licence before you let them start work, at the DBPR licensee search.
In Longwood
Why this happens in this housing stock
Capacitor failure is cited as the single most common Florida AC repair, driven specifically by heat and lightning-storm frequency — and Central Florida sees both in volume every summer. A capacitor that has failed quietly for weeks often finally gives out during exactly the kind of storm that also trips a breaker, so the two causes get confused with each other on the phone. Capacitor replacement cost.
The float-switch overlap with the not-cooling symptom is the same story here: the City’s own mechanical permit application flags attic-located air handlers and requires attic access at inspection, which tells you how common that installation is in Longwood’s 1970s and 80s stock. A full pan does not just stop cooling — on some systems it removes power to the whole unit as a safety measure.
Cost
What the fix typically costs
| What is being priced | Researched range | What moves it |
|---|---|---|
| Diagnostic visit | $75–$200 | Commonly cited Florida diagnostic or service-call fee. Some sources put Florida contractors at $65–$95, and the fee is frequently waived or credited toward the repair if the work proceeds. |
| Capacitor replacement | $80–$400 | Installed, nationally, averaging around $175. Florida-specific sources cite $85–$200 for a job that takes under half an hour. |
| Contactor replacement | $150–$350 | Parts and labour, Orlando market. |
| Control board replacement | $400–$800 | Control board; often requires a part order. |
These are researched market estimates, not a quote
Every money figure on this page is a published third-party range, compiled in September 2026 from the pricing guides listed in the sources at the foot of the page. They are here so you can sanity-check what a contractor offers you before you sign, not so you can hold anyone to a number they did not write. The one exception is the City of Longwood permit fee, which is the City's own published figure and is linked to its fee schedule.
Sources
- Smart Home Air & Heat, AC Repair Cost Orlando 2026 (Central Florida contractor, market ranges from 2025-2026 service data). https://smarthomeairheat.com/our-blog/ac-repair-cost-orlando-2026/
- Comfort Control Systems, “How Much Does AC Repair Cost in Florida?” 2026 price guide (third-party pricing guide). https://my-ccs.com/blog/how-much-does-ac-repair-cost-in-florida-2026-price-guide/
- HomeGuide, AC capacitor replacement cost (third-party pricing guide). https://homeguide.com/costs/ac-capacitor-replacement-cost
- City of Longwood Mechanical Permit application. https://www.longwoodfl.org/DocumentCenter/View/4604/Mechanical-Permit-application-PDF-
- Florida Statutes §489.105(3), definitions of Class A, B and C air-conditioning contractor. https://www.flsenate.gov/laws/statutes/2024/489.105
- Florida DBPR licensee search. https://www.myfloridalicense.com/wl11.asp
Figures are dated. Permit fees, rebate amounts and code cycles change — re-check the primary source before you rely on a number here.
Not getting anywhere?
Tell us the symptom, roughly how old the house is and roughly how old the equipment is. That usually narrows it to two candidates before anyone drives out.