Has Anyone Repaired an AC Unit?

[pbiJim]

You need to get a look at the inside of the system. Gauges are a good place to start. You may just have a plugged orifice valve & pent up pressure from that may have overloaded the compressor.

At the other end of the spectrum, If there is any black goo in there, that is called the black death. It means that moisture got inside & reacted with the chemicals that live in there & now you need much more than just the compressor. This often happens after someone fails to bring the system down to full vacuum before recharging it. A little moisture from the surrounding air is all it takes to cause really big problems.

There are many other possibilities too. You really want to find a reputable tech that knows what he is doing. 10 minutes of his time doing proper diagnostics will beat all the free advice that you might get from the internet.

Also, you now need a license (funny little green card) to buy some of the refrigerants in the US.

[Dulcesuenos]

We had our go out recently we had to have mermaid replace the capacitors etc in the box.
In the mean time we had to buy a window unit 1/3 the size of the big unit. Wife sewed a sunrella cover for the hatch and we fitted snaps to the unit to hold the skirt to the unit and mounted it at a hatch. There is no water run off as they are mostly flinger types that fling the condensate onto the hot compressor? And it evaporates that way. This $150. Unit cools our boat almost as good as the big one on 1/2 the electricity. Guess which one we leave running now.
Sounds like your particular problem could be one of two things a trick for is The guy at mermaid said to disconnect the water cooling lines going into the the unit and out of. Fill it with a 50/50 vinegar water solution and let sit 20-30 minutes. Then drain into a bucket. Nasty black stuff Will come out and your unit will cool so much better.
The other thing sounds like you have could have another restriction in your raw cooling water flow. We had a tiny blockage once at the venturi for the condensate water suction piece where it necks down, we still had flow but the overheat breaker would trip in 5-10 min it took forever to discover it , your ac pump should avg at least 1 gal a min on discharge or its clogged somewhere.

[scoobert]

Originally Posted by bobconnie

Gee Scoobert, I hope you got a survey on that boat of yours!! But if ya did he sure missed a bunch of stuff you have been haveing trouble with !! Just sayin I might talk to him if it were I!!

Being a genuis, i did the survey myself.
I only missed a dead battery, and the prop shaft seal.
I actually had both ac units marked as bad.
The rear works great

[psneeld]

It could be the control panel.

I know if some AC units try to cycle too fast without a delay or if you try to go from heat/cool...they will rotor lock and trip the breaker usually.

Don't know what kind of control panel you have...could you swap your panels (2 units) and see if the problem switches compressors? Maybe see if there's a way to bypass the panel/thermostat function.

Could be more work than other trouble shooting..but thought I would suggest it...

[ranger58sb]

If the problem really is a $700 compressor, especially if it's an old unit and uses old refrigerant, you might compare that to the cost of a new Vector Turbo.

Assuming you'll keep the boat for a while, and assuming AC is important where you are (or will be), a whole new marine unit might be more cost-effective in the long run.

-Chris

[scoobert]

This happens when the unit is steady on, not cycling

[HappyMdRSailor]

If you're still after a pump and want to repair, try an "appliance parts" store.... This place is in CA, but they can get just about anything... I have found their prices to be shockingly fair.... If they cannot get the exact part, or the price is too much, they have the ability to match actual specifications and suggest a "generic unit" or another manufacturer's part...

Appliance Parts from OCAP Supply - Appliance Repair Parts for Thousands of Appliances

[Hudson Force]

Originally Posted by scoobert

so my big AC is basically dead.
the compressor runs for a while, stumbles, and locks up............

I'm still questioning the interpretation of "stumbles an locks up". Afterall, this is a vague observation, right? 'just what you hear as the unit quits running. I'd still check for the simpler, cheapest and most common problem first. My own, well functioning unit, will "stumble and lock up" as it stops by it's overheat swith and also trips the breaker if I'm not quick to turn it off. This occurs when my intake filter basket is blocked by debris or a jellyfish. How have you evaluated the volume of cooling water? Have you actually cleaned the filter basket and fully cleared the through-hull? Have the heat exchange tubes been cleaned out? Do both of your AC units run on the same pump? Are they the same size units? If not, do you divert a greater flow of water to the larger unit? All this evaluation, that costs nothing, should be done before you start buying parts.

[motion30]

When my 16000 unit quit I priced a compressor at the marine air conditioning store, I also was quoted $700. I did some research and found the compressor was the same 120 volt unit used in small condominiums. I was able to buy a new compressor at the regular air conditioning shop for $350 new.

[HappyMdRSailor]

Originally Posted by motion30

When my 16000 unit quit I priced a compressor at the marine air conditioning store, I also was quoted $700. I did some research and found the compressor was the same 120 volt unit used in small condominiums. I was able to buy a new compressor at the regular air conditioning shop for $350 new.

My point exactly!

[DeepFrz]

If it runs for 15 minutes it sounds like it is overheating. One of the main causes of overheating is poor water flow.Have you thoroughly flushed the system out? Flush with fresh water, reverse flow and then flush with a radiator cleaner. Then try it.

Many AC units have an error code display. Do you have the manual for your unit?

[foggysail]

Originally Posted by sailorchic34

But I'm crazy that way...

.

NO WAY!!!

Foggy

[foggysail]

Some caution needs to be offered regarding gages. First, there is almost no chance your system is prepared for gages UNLESS it had refrigerant added by a prior owner!!! If none, you will need to add piercing bullets to pierce the lines in order to attach the gages.

Piercing the high pressure line must be done with care! It is high pressure and you run a real risk of it leaking later.

Piercing the low pressure is not so risky but it tells you only the low pressure.

Adding gages next.... WOW, this gets to more risks this time the risk of adding air to the system also purging refrigerant from the system. If you do not have a good understanding of all this, DON'T DO IT!


OK--- appears you recently purchased this boat so you don't know what is happened before you owned it. So my advice is to LOOK for a LINE PIERCING BULLET that might have been added by the previous owner for the purpose of adding refrigerant. THAT WILL BE AN IMPORTANT TIP OFF!!!!

If you find one attached to a line, most likely it will be attached just to the low pressure line, you probably have too much refrigerant in the circuit. Another way to help trouble shoot the problem is to measure the AC (alternating current) line current! Check it against the printed label on the AC unit. If the line current is above that specified and the line voltage is whatever the unit's marking is, my guess is that there is too much refrigerant in the system.

A tech should be able to tell and also remove some of the refrigerant for you.

[Hudson Force]

OK, Sccobert, 'all this talk of pressure guages and compressor costs....... You drive a truck for a living , right? So, let's say you're on the road and overheating. Are you going to buy a new radiator before you check the hoses? Seriouly, work from the simple low cost route first!

[transmitterdan]

I really don't think your AC is "basically dead" based on your description. This happens a lot on boat AC systems and it just sounds like the safety systems are protecting the compressor. The following two things you can try and will not hurt the unit and one of them might just fix it.

1) Check the temperature of the discharge water flowing out of the "bad" unit. Is it hotter than the other AC units when they are running? If so the flow rate may be too low. This can cause the compressor to lock up and trip the breaker. If you have a single water pump for all AC units plug up the other outlets and run just this one AC unit to see if that "fixes" the problem. If so there is some blockage in the hoses feeding or discharging that one AC unit. Find the blockage and clear it.

2) If the water temperature is the same for all AC units let a little bit of gas out of the unit via the schrader valves. Most units have these and they may be capped off with plastic or metal caps. But do this when the unit is not running and after it has been off for a few minutes. Unscrew the blue cap and push the center pin until it hisses. Only let out gas for about 15 seconds and then restart the unit. If it runs longer this time then you are onto the problem. You just need to have an AC tech put gauges on and get the right amount of gas. Your description is consistent with a combination of too much refrigerant in the system and warmer than normal cooling water. An AC unit that locks the compressor up during the summer months but runs fine during cold months may have too much refrigerant.

P.S. You can catch more flies with honey than vinegar.