Boat AC Not Cooling?
Start With the Evidence.

Restricted seawater flow from scale, a clogged strainer, pump or impeller problems, refrigerant loss, compressor faults, controls, sensors, and electrical issues can all produce warm-air symptoms. The correct repair depends on measurements at the installed system; a flush should not be prescribed until water-flow and temperature evidence support it.

Cost depends on the diagnosed cause, equipment make and model, access, refrigerant and electrical findings, parts, and approved scope. Accumar diagnoses first and provides an estimate for approved repair work rather than promising a price from the symptom alone.

Scale buildup is cumulative. In SWFL's warm, mineral-rich saltwater, 12 months of operation deposits enough calcium to reduce condenser efficiency by 30-50%. Systems that sat idle over winter are worse — stagnant saltwater accelerates corrosion and scale hardening. An annual descaling flush before summer prevents this completely.

You can do a basic vinegar flush, but it's only about 20% as effective as professional descaling. Professional-grade descaling solutions (like Accumar Descaling Solution) are formulated specifically for marine heat exchangers and dissolve calcium carbonate 5x faster than household vinegar. We also inspect the impeller, strainer, and refrigerant charge during the service — issues a DIY flush won't catch.

In Southwest Florida: every 12 months minimum. Liveaboards running AC 10-12 months/year should flush every 6-8 months. Boats in canals with hard water may need more frequent service. The cost of an annual flush ($200-400) is a fraction of the $2,000-3,500 compressor replacement that neglected scale buildup causes.

This is classic high-pressure lockout. The compressor runs until head pressure exceeds the safety limit, then the high-pressure switch shuts it down. After it cools, it restarts — and the cycle repeats. The root cause is almost always restricted water flow: scale in the condenser, worn impeller, clogged strainer, or partially blocked thru-hull. Left unchecked, the repeated thermal cycling destroys the compressor.

General rule: if the compressor is good and the unit is less than 15 years old, repair is usually more cost-effective. If the compressor has failed on a unit older than 12-15 years, replacement often makes more sense — newer units are 20-30% more efficient and quieter. We'll give you an honest assessment. We don't push replacements when a $300 repair will get you 5+ more years.

Most new non-urgent work is currently scheduled about 3–4 weeks out. Urgent requests are reviewed during business hours. Technician availability, travel, safe access, parts, and response timing are confirmed case by case; first-visit completion and after-hours service are not guaranteed. A diagnostic visit does not guarantee repair completion at the first visit; completion depends on the findings, equipment, access, parts, and approved scope.