Frigoboat - Frigomatic AV 35 F - Problem

[mcerdos]

Hello,

After 8 years of trouble-free use, my freezer is now giving me some issues.
I noticed the ice cream was soft. The next day, it was softer still. A quick look inside the box confirmed the evaporator was only partly frosted.

I removed the low-pressure cap on the compressor and vacuumed the system for about 30 minutes. Then, I slowly replenished the R134 refrigerant. I used a sniffer to check for leaks and didn't find any. After doing this, the freezer maintained about 12°F (-11°C) for about 4 weeks without issue.

I kept a close eye on it. Then, one morning I noticed the inside box temperature was up to 27°F (-3°C). Looking inside the box only half of the evaporator was frosted. Moving some stuff around inside, I bumped the very thin copper tubing attached to the evaporator a couple of times. I notice the evaporator starting to get very cold again and closed the lid to see what would happen.

For the past week, it has maintained about 15° (-9°C). Then, one afternoon, it went to 27° (-3°C). again. I tapped the copper tube again with a pair of pliers and now it seems to be working again (for the past 3 days) staying less than 15° (-9°C).

Any ideas about what is going on here would be greatly appreciated.

Many thanks.

[SV Confianza]

can you take a picture of which thin copper tube you are tapping?

Also if you haven’t replaced the orings on the quick connects, they go bad after a while. See here: https://coastalclimatecontrol.com/bl...oat?format=amp

We have an 18 year old frigoboat system, and I’ve gone through lots of the possible issues already…

[mcerdos]

Originally Posted by SV Confianza

can you take a picture of which thin copper tube you are tapping?

Here you go.

[mcerdos]

Originally Posted by

Also if you haven’t replaced the orings on the quick connects, they go bad after a while. See here: [URL="https://coastalclimatecontrol.com/blog/changing-o-rings-frigoboat?format=amp"

https://coastalclimatecontrol.com/blog/changing-o-rings-frigoboat?format=amp[/URL]

Thanks for this suggestion but I would think the sniffer would detect the leak. I did sniff around the joints. Also, it wouldn't suddenly go back to working again if there was a leak, right? It seems the box would slowly get warmer.

[SV Confianza]

From your description, it sounds like a capillary tube blockage. There's a description in the manual for dealing with this:

15.4 - OBSTRUCTED CAPILLARY (PARTIALLY)
The unit whilst being recharged, does'nt show any increase of efficiency: it means the capillary is partially obstructed. You could also get an erratic efficiency: it means the obstruction is moving inside the capillary. Unscrew 4,5 turns the quick connect between the dryer and the capillary and operate the until till you get 0 pressure in the low pressure side. Replace the evaporator: if you don't have one new on hand you can try to repair the evaporator by blowing high pressure (al least 140 P.S.I./10 Bars) of dry air or nitrogen from the capillary quick connect hoping the obstruction will be blown out. If so you should notice by mesuring an encrease of the air flow off. The repaired evaporator should be reconditioned with Refrigerant before beeing connected back to the condensing unit.

However, I've had some odd behavior as well, and I wonder if there's more to the story. If it's a capillary blockage, how did it get there? If it's moisture blocking, then that would indicate a leak (refrigerant leaks out, moist air leaks in). I've also seen someone report that their compressor must have gotten hot enough that it altered the oil that's in the lines, and it was a yellow color instead of the normal clear/brown. I always see a tiny bit of oil in the quick connects when I disconnect mine, and it's a light brownish clear color.

Is that your return line (the low pressure side) that's frosted up past the evaporator? How far? It could actually be overcharged if that's the case. Then the liquid refrigerant is going past the evaporator into the return line. Half of the cold plate could be frosted toward the return side in that case.

My setup is a K35F connected to a Frigoboat refrigerator box, so it looks quite different. A little hard to compare. I'm sure there are more knowledgeable than me...

I had an experienced frigoboat guy helping me troubleshoot once, and he told me that a properly charged frigoboat evaporator should sound like popping popcorn. Rapid popping noises. Some popping/some fluid moving sounds is bad. Gurgling means undercharged (but I've also found it can mean significantly overcharged).

The silly things are so sensitive to the amount of refrigerant, I will charge little squirts at a time, wait 10 minutes, listen to how the sound changes, then add some more.

Many folks have also recommended testing the amperage consumed by the compressor as a method of troubleshooting. I have not needed to use this method in the past, but there's lots of threads on the net about it.

Hope some of this helps...

[SV Confianza]

Oh also I forgot about the cap tube filter that could be a solution. https://www.coastalclimatecontrol.co...lter-p95699110