Frig-o-boat Freezer and Refrigerator

[Black Diamond]

I have a frig-o-boat freezer and refrigerator. Its a 12V system that has worked fine for the past 5 years. I like the system. It has separate compressors for refrigerator and freezer and our box is well insulated.

A couple of weeks ago the freezer was working fine and then suddenly the temperature started to get warmer. It finally ended up with me shutting it off and then contacting someone to recharge the refrigerant. They did this, and also put a dye pack in with the coolant to see if there were any leaks. This happened to my refrigerator the prior year and the recharge did the trick.

The freezer worked fine for a day or so and then reverted to the above behavior. I called the service provider back out to fix what they didn't before. They told me that the dye pack did not show anywhere they checked in the boat. They said they could not do anything until I hauled the boat as the problem was probably in the cooling plate.

This sounds fishy to me. I've never heard of the plate being a problem and / or leaking coolant into the ocean. This seems what I am being told however.

Anyone got any ideas?

Rick
S/V Black Diamond
Portsmouth, RI

[skipmac]

By cooling plate are you referring to what Frigoboat calls the keel cooler, a through hull fitting where the compressed refrigerant is cooled?

If so, yes I have heard of them failing. Could easily be due to corrosion or galvanic action with different metal parts immersed in salt water. I have also heard of leaks in the keel cooler allowing salt water into the system corroding everything and requiring a complete replacement, compressor, evaporator and all the lines.

I have to say the logic sounds believable to me, assuming the problem was loss of refrigerant which sounds likely. So system doesn't work, tech adds refrigerant with dye, system works for a while and quits, no dye trace found inside the boat. So where else might the leak be?

[Richard Kollmann]

As long as compressor is confirmed to be running and evaporator is warm there is probably a refrigerant problem. If evaporator has frost anywhere on evaporator but not fully frosted refrigerant is low. A service Tech may not be able to tell difference on this system between low on refrigerant and refrigerant blockage.

Many times it is a poor seal inside servicing cap where the leak is. With only 3 ounces of refrigerant in this small system it can leak out fast if cap seal is weak.

There have been many more reported refrigerant problems on Frigoboat systems than any other small 12 volt icebox conversion unit. Service techs do not like to work on these systems because it normally takes hours and several service calls to find and correct the problem. Of all the problems I have reviewed on frigoboat systems the only pattern I would link to loss of refrigerant is reported seems to be at five years line connector O rings have leaked. When you buy a system dealer gives out a few spare O rings so they are aware of O ring problem. I do not like O ring seals in line connectors because replacements must meet the design gap and approved material. The chances are any O ring you buy locally will not meet connector manufactures Metric Design spec and have a shelf life of less than one year.

Yes, there have been a few keel cooler refrigerant leaks but it is the last place to suspect as leaking outside the hull. When leak testing lines inside boat check keel cooler through hull, See Picture.

On a keel cooler system there are three to a possible of six line connectors if extension tubing was needed. Any one of these connector’s O ring sets could have failed do to age, heat, lack of lubrication or incorrect original size. O rings come in various materials, diameter sizes and wide range increments of .005 thicknesses. Material used in US for 134a efrigerant O rings is Hydrogenated Nitrile color Green. Also in this country Blue Neopreme and Green O rings are interchangeable with 134a, blended refrigerants and R12.

The weakest O ring link in refrigerant flow chain would be at line connector between compressor and keel cooler as this one sees the highest temperatures at times of maybe 200 degrees F.