01
Intake & seacock
Seawater must enter through an open, unobstructed intake.
Marine air conditioning
Cool cabins need airflow and seawater flow.
Marine A/C adds an entire water circuit to the comfort equation. Sunset Air & Services checks the cabin side, seawater side, controls, drainage, and refrigeration system before recommending a repair, maintenance, or descale.
Follow the water
A cooling problem can begin anywhere in the seawater path.
The pump may be running and the system may still have poor flow. Looking at the complete path prevents a dirty strainer, closed intake, airlock, weak pump, fouled condenser, or restricted discharge from being mistaken for a refrigerant problem.
02
Sea strainer
The basket catches grass, shells, growth, and debris before they reach the pump.
03
Seawater pump
The pump must stay primed and move enough water for every operating A/C unit.
04
Condenser or chiller
Heat from the cabin transfers into the seawater circuit here.
05
Overboard discharge
Visible discharge confirms water is leaving the circuit, but strength matters too.
Book the right marine visit
Known fault means service. A working system can receive maintenance.
Marine service call
Choose service for no cooling, no water discharge, a pump that will not run, recurring error codes, leaks, ice, breaker trips, or a zone that is not operating correctly.
Marine maintenance
Choose maintenance when the equipment is operating and needs filter, drain, strainer, water-flow, controller, electrical-condition, and performance checks.
Descale service
A descale is a planned seawater-circuit cleaning based on flow, operating symptoms, growth conditions, service history, system layout, and access—not an automatic refrigerant repair.
Stop before opening water or electrical equipment you do not know.A wrong seacock, unsealed strainer, energized panel, or pump running dry can turn a comfort problem into vessel damage. When in doubt, note what you see and call.
Marine owner self-check
Eight useful things to check and report.
These observations help narrow the problem without asking a boat owner to open refrigeration or electrical components.
01
Controller, power, and error code
Set the controller to COOL, lower the setpoint, and allow for its normal start delay. Note whether the display is blank, shows an error, or repeatedly stops. Check only the labeled A/C breaker—do not remove electrical covers or keep resetting a breaker that trips.
02
Cabin blower and airflow
Listen for the blower and feel the supply vent. Note whether airflow is strong, weak, warm, cold, or missing. Check the return-air filter and make sure luggage, cushions, or stored gear are not blocking the return or crushing a duct.
03
Overboard water discharge
From a safe position, look for the marine A/C discharge while the unit is calling. Report whether it is strong, weaker than usual, intermittent, or absent. No discharge is a reason to stop the A/C rather than let the pump run dry.
04
Sea strainer condition
If the bowl is visible, look for grass, shells, slime, or growth. Only open and clean a strainer if you already know the correct seacock and safe procedure. The A/C must be off, the correct seacock closed, the cap resealed, the seacock reopened, and the system checked for leaks and prime. If you are unsure, leave it alone and call.
05
Seawater pump
Note whether the pump starts, sounds different, cycles, or becomes unusually hot. A pump can run without actually moving water when it has lost prime or has an intake restriction. Do not run it dry or disassemble it onboard unless you are qualified.
06
Recent haul-out or airlock
Tell us if the boat was recently hauled, the strainer was opened, a hose was removed, or the system sat unused. Those details can point toward lost prime or trapped air even when the pump can be heard.
07
Leaks, drains, and standing water
Look for seawater leaks at accessible hoses, fittings, clamps, the strainer, and pump. Also check the A/C drain pan and condensate hose. Stop the system for an active seawater leak, water near electrical parts, or a pan that is overflowing.
08
Last maintenance and descale
Record the last filter cleaning, sea-strainer cleaning, and condenser descale if known. “Unknown” is useful information. Also note whether discharge flow or cooling has slowly weakened since the last service.
What is a marine A/C descale?
It cleans the inside of the seawater circuit where a brush cannot reach.
A professional descale isolates the raw-water circuit and circulates a purpose-made marine descaling solution through the condenser or chiller water path. The solution loosens or dissolves marine growth, calcium, lime, rust, and mineral deposits that restrict flow and reduce heat transfer. The circuit is then flushed with fresh water, returned to normal operation, checked for leaks, and verified for discharge flow and cooling performance.
This is not the same as cleaning the strainer, and it is not a reason to pour household acid or an unapproved chemical into the system.
When it may be time
No honest schedule fits every boat.
Water temperature, saltwater growth, run time, vessel use, system design, and past service all matter. These clues justify a closer look:
- Overboard discharge remains weak after the strainer and intake are confirmed clear
- Recurring high-pressure or seawater-flow faults
- Cooling performance has slowly dropped even though cabin airflow is good
- The condenser, chiller, or seawater circuit has an unknown service history
- The vessel lives in warm saltwater or sees heavy growth and long run time
- A clean strainer and running pump still do not produce normal system flow
Help us arrive ready
Tell us about the boat, access, airflow, and water flow.
Marine service goes faster when the appointment includes the vessel and system details—not just “the A/C is not cold.”
- Vessel name, make, approximate length, marina, and slip or dock location
- Shore-power availability, gate or dock access, parking, and any marina check-in rules
- Controller brand, displayed error code, and which cabin or zone is affected
- Whether the blower runs, seawater pump runs, and overboard discharge is strong, weak, or absent
- Sea-strainer condition and the last known maintenance or descale date
- Equipment access: under a berth, behind cabinetry, in an engine room, machinery space, or another tight area