How To Get A Fish Out Of A Sailboat AC

How To Troubleshoot Your Sailboat AC Unit

How to get a fish out of my sailboat air conditioner. Now that’s a phrase I never thought I’d need to Google. But here we are.

The AC stopped working and had a HP (high pressure) warning. That’s all the info I had…oh, and the fact that it’s blazing August heat in Texas.

The sailboat air conditioner works differently than a house AC. It pulls water into the cooling system and pushes warm water out. The water is where the heat is transferred from the air.

In a house AC, the heat transfer occurs in that big fan outside the house.

Naturally, this means anything under the boat can get sucked into the system.

Why Does Our AC Get Clogged?

There are a few ways the AC can get clogged and shut down. Fortunately, the solutions are rather simple.

Clean Strainer and Bromine Tablets

Most air conditioners get clogged in the water strainer. This is a cylindrical filter that keeps shrimp, grass, shells, and other large debris from entering the water pump, which runs the water thought the air conditioner.

Our strainer stays rather clean. We place bromine tablets in it to kill any algae or plant growth, and we clear the strainer every week or so.

Then there’s the actual water inlet.

Clearing the Seacock

The inlet is about 2-2.5 inches in diameter and comes into a seacock, which is a large bronze valve (some are plastic). The problem in our boat is that the seacock immediately has a right angle, and that angled brass fitting also decreases in size to match the plumbing, which is 1.5 inches.

Fish that eat off the bottom of the boat are strolling along their algae buffet, and then get sucked into the inlet!

Some boats have an additional strainer on the outside of the inlet to keep large debris from entering.

The additional strainer is a great idea, but if it gets clogged (i.e. plastic bag, barnacle growth) there’s no way to clear it without diving.

And in our water…diving is not so clean and easy.

For my sailing friends, let’s get a little technical on the AC unit…these are a few things I’ve learned.

Troubleshooting the AC Unit on a Sailboat

This is a typical AC water pump. It’s an Amazon link, so you can see what they cost. Not bad price considering they last for 10+ years.

Time needed: 25 minutes

How to Clear the HP (HPF) Warning on Sailboat AC Unit

  1. Understand What the HP Warning Means

    We have a cruisair AC, but all AC units have the high pressure function. If this is happening during a cooling cycle, it is likely because of a lack of water flow. If it is going on during a heating cycle, it is probably due to lack of airflow. In our case, it was through a cooling cycle.

    You can see the lack of water flow on the exterior of the sailboat. There should be water shooting of out the side when the AC is on.

  2. Check The Water Pump Motor

    See if the motor is running. Place your hand on the motor and turn on the AC. You should feel the motor kick on.

  3. Clean The Water Pump (Bonus Step)

    Every year or so, it’s not a bad idea to disconnect the motor and clean it. Just remove any gunk that’s built up in the impeller and water pipes.

  4. Testing the HP Warning On The Circuitboard

    We don’t do this step. However, if you have no other options it could be your last resort.

  5. Clear The Water Line

    This is our most valuable step. Simply flush the water line. Usually the HP warning is due to a clogged intake or strainer. Clean the strainer. Then use a high pressure nozzle on a water hose to backflow the system. Place the hose on the water outlet, turn the water on, and allow the water to push through the system and out of the seacock. If this doesn’t work, you’ll need to take the system apart (see our video above).

This high pressure water hose nozzle will work wonders for you in many ways. It’s the exact nozzle (see below, an Amazon link…when you shop it helps our journey) we use to spray the sale off the boat, wash the anchor locker, and clear the HP warning from our sailboat AC unit.





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