Ellis Boat Company
You don’t have to be a professional to troubleshoot A/C. Problems are often simple to fix. First, check for a steady flow of cooling water from the discharge. If that’s not happening, the strainer could be clogged. Next, check the pump impeller. Impellers on A/C units are not usually self-priming, and sometimes air gets into the line and starves the pump for water. Prime the pump and try again—check the manual for instructions on how to do it. Finally, if the cooling water’s flowing but the A/C still isn’t working, the evaporator screen might be covered. Clean it carefully with a vacuum or soft brush.
Most important is to keep the water flowing freely. Clean the strainer every couple of weeks and keep the air filters clean, as you do with your home A/C. Ensure the drain pans are flowing freely. Occasionally, maybe every 18 months in the Northeast, the condenser will need cleaning. To verify your system is working right, check the temperature difference between the warm air going into the unit and the air coming out. It should be between 15 and 20 degrees. If it’s less, generally it means the refrigerant is low, or there’s a leak. More, and the evaporator is clogged. In both cases, it’s time to call the technician.
I’m the licensed captain of an 86-foot expedition yacht.
Besides keeping the sea strainers clean (I do it once a week), the most important thing is to clean and descale the condensers at least twice a year. A condenser can get growth in it even sitting at the marina. If it’s running hot, it needs cleaning; you should be able to keep your hand on it. Older condensers use copper coils, but the new ones are titanium, and if you keep them clean they’ll last for many years. I do it myself using a Port-O-Flush Jr., a five-gallon bucket with a pump, to run a chemical descaler through the system to keep things moving.
Know how much water should pump out of the exhaust and what the compressor should sound like. If the water flow decreases, there’s usually a clogged strainer, or the
condenser tubes need cleaning. We flush out growth and scale with Rydlyme Marine, a biodegradable de-scaler. Our pump-and-bucket setup circulates Rydlyme through the whole water system of the A/C, then returns the used product to the bucket through a strainer, so we see any heavy debris that flushes out of the system. Do this whenever the water flow slows down, if cleaning the raw-water strainer doesn’t fix it.
This article originally appeared in the July 2019 issue.