1995 Hunter 336 Air Conditioner

stm11

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Aug 22, 2020
14
Hunter 336 Cocoa
I own a 1995 Hunter 336. Today, I turned on my factory installed air conditioner and received the following error message: "High Freon Pressure I/O Lockout" (see attached photo). Needless to say, my AC was only blowing hot air. I have never received this message, so I do not know what it means. I can only assume I need to add Freon. I have a few questions: First, has anybody ever received this error message? If so, what does it mean? Second, where the heck is the factory installed unit located? Once found, how is Freon added? Is it the same as an auto Freon connection? Lastly, do anyone have any pictures of their Hunter AC units so I know what I am looking for? Thanks in advance.
 

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Nov 6, 2006
9,900
Hunter 34 Mandeville Louisiana
Generally, high freon pressure means that the condenser is not getting enough sea water flow.. Thru hull plugged, ac strainer plugged, failed ac pump also (failed high freon pressure switch)would be the first places to poke around in.. Hope ya find it!
 

stm11

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Aug 22, 2020
14
Hunter 336 Cocoa
okay thanks....I am new to sailboat repairs. So where would that be? I realize it would be below the water line. How about the location of the freon pressure switch? Any pictures would help tremendously.
 
Last edited:
Nov 6, 2006
9,900
Hunter 34 Mandeville Louisiana
Sorry I can't help with that.. I don't know the particulars of your installation.. Some air conditioners were factory done and many were owner or dealer installed.. The pressure switch probably cannot be changed except by removing the freon and then evacuating and recharging.. not fun and best done by an air conditioner technician.. The sea water stuff can be done by following the water hoses from the condenser, which will be near the compressor unit.. one hose will go to an overboard discharge, usually slightly above the waterline, and the other hose will go to an electric pump that runs when the compressor runs (on most units.).. from the pump, a hose will go to a strainer, then from there to a thru-hull valve . that is where the water comes into the boat, thru the strainer, through the pump, thru the condenser and then overboard.. Best done if ya have a buddy who knows how the system works.. The strainer has to be periodically cleaned out and the period will vary with how messy the sea water is at your location. Typically, you'd close the seawater valve, remove the strainer basket, clean it, then replace it and open the sea valve.. some units have to be "burped" to get water back to the pump after cleaning the strainer.. Again, the first couple of times ya do it, it'd be best to have a boat buddy with ya..bribery with cold beverages works well! (after the work is done)
Attached is my unit, the fat coiled tube is the condenser, water from the pump goes into the bottom of it and comes out the top tube and overboard.. Yours will probably look similar..
P9180694_LI.jpg
 
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stm11

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Aug 22, 2020
14
Hunter 336 Cocoa
Thank you very much. I've found some YouTube videos and understand the operation process of the AC. I just have to find the darn thing (location) on my boat. Wasn't how I planned to spend my holiday weekend. I really appreciate the info and have a friend who is very knowledgeable of sailboats. Thanks again.
 
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Jul 6, 2017
158
Hunter H 41DS Hampton, VA
Not enough cooling water getting through the unit. Either the line is clogged, seacock is closed, strainer is plugged or there sea water pump isn't running. How often do you clean the strainer?
 

stm11

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Aug 22, 2020
14
Hunter 336 Cocoa
Tim, first and foremost, thank you for your reply. I hadn't ran the AC for 6 or 7 months. This past week was the first time I had an issue. As stated, I am new to sailing and things I learn on this forum, YouTube, and other resources are bring me adept to new things daily. Anyhow, to answer your questions, I hadn't cleaned the strainer. I just changed the impeller, fuel filters, belts, oil, oil filter, checked coolant, and other engine components. Until this post, I honestly wasn't aware of a strainer. I just had a new bottom paint job, prop paint, and zincs replaced. I've watched several You Tube videos and I have another question, isn't the raw/sea water pump inlet (seacock) the same for water circulating through the engine for cooling? If so, I know there isn't any issue there. I am definitely not happy to encounter this issue. Thanks again...
 
Feb 14, 2014
7,444
Hunter 430 Waveland, MS
isn't the raw/sea water pump inlet (seacock) the same for water circulating through the engine for cooling?
Normally NO!
Jim...

PS: Did you have a Survey done before buying your boat?
 

stm11

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Aug 22, 2020
14
Hunter 336 Cocoa
I didn't know...hence why I ask. Yes. I had a survey done and I had very minor issues, nothing mechanical. A/C, engine, sanitation, etc. were fine.
 
Feb 14, 2014
7,444
Hunter 430 Waveland, MS
I had a survey done
All of the through hulls [with seacocks] should be called out on that Survey.

Look at the bottom of boat drawing. Your AC cooling water should be noted there.
Jim...

PS: I can stick with your questions for a while tonight.:)
 
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Jun 21, 2004
2,533
Beneteau 343 Slidell, LA
Think that it’s best if you hire a marine air conditioning tech to check out the system and do the repair. Be sure to be there so you can ask about the basic components of the system and how it operates. Also watch how to clean the water strainer and return air filter. I don’t think you are ready to assess the
refridgerant level and service at present, and it probably doesn’t need it. Take one step at a time; it takes time to learn about these systems and even longer to learn how to repair them . One bit of advice is to run the AC/heater at least every 30 days. Run it in the AC mode as well as in the heat mode to prevent the reversing valve in the condenser unit from getting stuck. Good luck with the repair!
 
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Likes: JamesG161
Jul 6, 2017
158
Hunter H 41DS Hampton, VA
There should be a separate strainer and seacock just for the ac system. Not the same as the engine raw water strainer.
Some peeps get barnacles growing inside the raw water lines. We get jelly fish clogging our strainer in late July.
Your ac control panel has a relay that turns on the separate raw water cooling pump.
Someone also mentioned trapped air. That can be an issue as well. Just need to bleed the air with the pump running.

Not sure how your boat is set up but all my seacocks are run thru the hull at just two locations. Makes life easier.

You should exercise all your seacocks once a month.
 

stm11

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Aug 22, 2020
14
Hunter 336 Cocoa
Update: So to all those who provided information, guidance, and constructive criticism: Today I completed this task myself. I found the seacock, of course closed it, removed the strainer (filter), and cleaned it. It was somewhat dirty, but I do not think it was my issue. A Youtube video let me know the A/C intake water pump is not self-priming. Upon inspection, I realized there was air in the line. I first tried to extract all the air, induce water in the line, but that did not work. I went to my local hardware store, bought a $3 male water hose fitting, attached the hose, connected it to the garden hose, turned it on, & the error was gone. Lastly, I cleaned all the lines with a marine cleaning solution and whala... I ran my A/C (and heat) system for approximately 3 hours, checked for leaks...no problem. Thanks again.
 
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