Corrosion control: the Miami half of maintenance
Within a few miles of Biscayne Bay and the Atlantic — Miami Beach, Aventura, Key Biscayne, Coral Gables, anywhere east of US-1 — an outdoor unit ages about twice as fast as inland. Maintenance that ignores that is a checklist from somewhere else.
- Fresh-water coil rinse
- Every visit, and monthly by the homeowner with a hose (power off). Salt that sits on aluminum fins turns to the white, crumbling corrosion that ends a condenser at year eight.
- Coil coating inspection
- Factory coatings chip; a touch-up coating at the tune-up on a coastal unit is cheap and extends coil life materially.
- Electrical terminals
- Contactor, capacitor terminals, disconnect lugs, the low-voltage strip: cleaned and protected. Green terminals are the number two cause of a Miami no-start.
- Cabinet and pad
- Rust at the base, the fan shroud, the tie-down hardware. The hurricane tie-down is a code item; corroded anchors do not hold.
Hours a year a Miami system runs. About 4,190 cooling degree days against roughly 140 heating degree days (NOAA normals; climate zone 1A). There is no off-season to reset the drain line, rest the capacitor or let the coil dry out — which is why Miami maintenance is twice a year, not once, and why a ten-year-old Miami unit has the run hours of a fifteen-year-old one anywhere inland.
The rest of a Miami tune-up
After the corrosion items, in the order they prevent calls:
- Condensate line flushed and treated, flow proven at the outdoor stub, float switch tested or installed. Algae grows in the line twelve months a year here.
- Refrigerant charge by superheat and subcooling. A system that runs every day cannot carry a marginal charge for long.
- Evaporator coil inspected and cleaned. Humid bypass air grows biofilm on the coil face; it is also where a musty smell comes from.
- Capacitor measured against rating and replaced if more than 10% low. It has been hot and running since the last visit.
- Static pressure and temperature split recorded. Attic ducts in Doral, Homestead and Pembroke Pines; garage air handlers with long returns in Kendall and Hialeah.
- Heating side in November: heat strips staged and amp-measured, sequencer checked, heat pump reversing valve and defrost exercised. It will run ten nights a year, in January, at 2 a.m.
- Post-storm check on request: a unit that stood in water, or one that took a surge when power returned, before it is switched back on.
Where in Miami-Dade and Broward
Coverage runs from Homestead and the Redland north through Kendall, Pinecrest and Coral Gables, the City of Miami, Doral and Hialeah, Miami Beach and Aventura on the coast, and into Hollywood, Pembroke Pines and Fort Lauderdale. The visit changes with the address: coastal units in Miami Beach, Aventura and along the Fort Lauderdale beach get the corrosion items first; inland concrete-block homes in Hialeah, Westchester and Kendall get the drain line and garage air handler first; condos in Brickell and Sunny Isles get whatever the building's rules allow, which we ask about before dispatch.
When, in Miami
There is no shoulder season to hide the visit in, so the timing is about beating the peak:
| Month | Visit | Why |
|---|---|---|
| March | Main tune-up | Before the late-May peak; the coil, drain and charge set while contractors have slots. |
| June–October | None scheduled; hurricane season | Filter monthly, hose the condenser monthly, vinegar down the drain cleanout. After any storm, an inspection before restart. |
| November | Second visit | Heating side exercised, corrosion re-checked after a wet summer, drain re-treated for the winter. |
| Every 30–45 days | Filter | Twelve months of runtime; the 90-day filter label does not apply here. |
Condo maintenance: what the building usually allows
A large share of Miami-Dade and Broward housing is condominium — Brickell, Miami Beach, Aventura, Sunny Isles, the Fort Lauderdale beach. The equipment is a small split with the condenser on a balcony, a roof or a mechanical floor, or a through-wall packaged terminal unit. Building rules decide what an outside contractor may touch: many associations allow any licensed contractor to service the indoor unit and the filter but require their own vendor or an insurance certificate for anything on the roof or in a shared chase. Before we dispatch we ask three things: where the outdoor unit is, whether the association has a vendor requirement, and whether a certificate of insurance has to be on file with management first. A salt-air coil rinse on a balcony condenser is the single highest-value maintenance item in these buildings and the one most often skipped, because nobody can reach it without the building.
FPL, licensing, permits
Florida Power and Light does not pay for maintenance. Its instant $200 A/C rebate applies to a new system installed by a Participating Independent Contractor, which becomes relevant when the tune-up finds a corroded coil or a compressor near the end. FPL residential programs. Maintenance needs no permit in Miami-Dade; a replacement does, through Miami-Dade County Building or the city. The tech who connects gauges must be with a Florida-licensed (CAC or RA) contractor, which every contractor in this network is.
What maintenance costs in Miami
Miami labor sits toward the top of the five metros, and the coastal items add work. Twice a year is the honest plan here:
- $120–$260Standalone tune-up: coil rinse and inspection, drain treated, charge by subcooling, capacitor, terminals, numbers recorded
- $60–$180Coil coating touch-up on a coastal unit, added to a visit
- $220–$420 / yrTwo-visit plan, March and November, priority scheduling in summer
- $380–$650 / yrPremium plan: two visits, priority during heat and after storms, 10–20% repair discount
- $40–$130Float switch installed at a visit
- $90–$200Post-storm inspection before restart
If the November visit finds the strips or the reversing valve gone, the Miami heating repair page has the costs. The full tune-up checklist and plan comparison for any metro are on the maintenance page. Hurricane season outlook: National Weather Service Miami.