Cruisair AC Refrigerant

[Obi Wan]

My Cruisair STX16-HV 16000 BTU air conditioner worked fine the last couple of years and when I used a few months ago. But I fired it up this weekend and there was no cold air. Everything is working fine. Turns on, compressor kicks in, good water flow. So I assumed the Refrigerant leaked out somehow. I figured I might be able to recharge it myself - all I needed to do was look up what type it was in the manual. Here's what it says:

"the refrigerant gas used in the air conditioner is good for the life of the system."

Obviously not. It's not that old. I find it amazing that such an expensive air conditioner can not be serviced.

Has anyone else experienced this?

[Obi Wan]

So no one has serviced (or not) their Cruisair AC?

[a64pilot]

I believe they are sealed, which means to service it, you have to solder on service ports, or I think there is a clamp on type that probably leaks, so I'd solder some in.
If you do that then of course you have to have a good vacuum and set of gauges, helps if you know the exact weight of refrigerant and add a good set of scales to that list.
However it is extremely uncommon for them to just lose refrigerant, especially all at once like that, and if it did, the re servicing it isn't going to work as you have a large leak that must be repaired first.

More likely I think a stuck reversing valve or other problem.
Find the reversing valve and rap on it with the plastic handle of a screwdriver when it's running, if you hear a whoosh and it starts cooling, the valve was stuck. Not all that uncommon for the reversing valve to stick

[Obi Wan]

I did switch back and forth between heat and cool to see if that helped but no luck

[witzgall]

The Cruisair should have service points. However, refrigerant, if low, leaked out. It does not get used up, so that means anything you put into it will also leak out. How fast is the question.

A64 is correct about the reversing valve.

You can try and add some refrigerant, SLOWLY, and watch the frost/cold line. This process should happen a few seconds of refrigerant at at time, assuming you do not have gauges.

If all of it has leaked out, then adding more will not help at all, as there is no longer a vacuum in the system. At this point, you either need to find and fix the link, and then vacuum and recharge, or swap it out for a new unit.

A pro will test first for pressures in the system, this will tell you lots on what is potentially going on. If you are handy, you can buy a set a gauges and do this yourself.

Chris

[hellosailor]

Obi-
This is not like filling a new water pitcher for the kitchen table.
If you are going to mess with AC systems, first you need to find the leak, which means leak detection equipment and gas and the proper fittings to get it into the system. Then, assuming you can find the leak, you need to fix it, partly because the law often requires that, partly because if the leak isn't fixed, it will empty out again.
Oh yes, if the system has been "open" for any length of time, it may need to be flushed, because moisture creates acids that eat it out from the inside. And there may be a receiver/drier cannister that needs to be replaced.
And then, once you're all cleaned up, you need the right gas and oil and usually a gauge and hose set to refill it properly.
And that's ignoring legalities of working on one without a license.

Bottom line? It can be VERY expensive to do the job and do it properly. And an expensive total waste to do it improperly. If you don't have experience with AC, and don't want to do the whole learning curve, either find a tech who can do it (not always easy) or bite the bullet and think about a new system.

Championship golf, championship poker, olympic sports...all these things are easy, right? Same thing for AC systems, there are lots of little things that make it harder than it might seem. DIY is good, but with AC systems, you really need to do it right--or not at all.

[a64pilot]

Originally Posted by Obi Wan

I did switch back and forth between heat and cool to see if that helped but no luck

Did it heat? Did you hear the whoosh as it switched modes? You really should hear the whoosh if the valve is functional, it's quite loud.
Of course it's gas making the noise, so no refrigerant, no whoosh.
Most systems I thought had low pressure switches that prevented the compressor from running with too low a refrigerant?

[Obi Wan]

Originally Posted by hellosailor

Obi-
This is not like filling a new water pitcher for the kitchen table.

OK,
I screwed up again and started a thread without listing all of my qualifications.
Yes, I know a bit about A/C, having installed a few (not in boats) and serviced them, including repairing a leak with silver-solder. Yes, I have the gauges and servicing manifold (though it's a bit old). - the comment about the water pitcher is a bit condescending.

I was just asking if anyone had the same problem and if they had serviced theirs despite what the manual says or had any other suggestions before I tear into it or hire someone else to, or replace it.

[Obi Wan]

Originally Posted by a64pilot

Did it heat? Did you hear the whoosh as it switched modes? You really should hear the whoosh if the valve is functional, it's quite loud.

Unfortunately it's not a very conducive environment for listening. The twin generators running (no shore power) make quite a bit of noise. I can't tell if it's switching to heat because it's already 94 degrees in there. I'm going over there today to try again and taking a thermometer to see if there is any difference between ambient, "cool" and "hot".

[Obi Wan]

I assume that's the reversing valve in the middle?

Those also look like servicing ports (the red and blue). I haven't removed the plastic seals yet to investigate.

[a64pilot]

Yes, that gold thing with the three copper tubes is the actual valve, the solenoid is the thing mounted to it with a wire coming out of it.
Use the screwdriver as a stethoscope trick and see if you can hear the solenoid click when you go from heat to cold, and tap the reversing valve itself with the plastic handle.
The red and blue things sure look like servicing caps to me, they will unscrew of course if they are, and the type / size will tell you if R-134a or not, unless it's a very old system, I'd bet 134a.

[a64pilot]

You can also usually hold a solenoid and feel it click too.
On edit, nothing on a boat is supposed to be as accessible as your unit, it's supposed to be mounted upside down underneath and behind something immovable so that you can only view it with a mirror

[Obi Wan]

[emoji3]Yes, but had to give up closet space!

After doing research looks like it takes R401a

[a64pilot]

I have one behind my Settee, and the other under our bed. I try my best to make things accessible even if I have to give up space to do so, one day I will have to maintain it, if nothing else to clean the evaporator filters.
I don't have any experience with 401 myself. My license is I think for high pressure systems so I assume I can do 401 but do not have the equipment

[Obi Wan]

So I ran it again, and felt the solenoid for the transfer valve. When I turned the AC on, the solenoid clicked just before the compressor kicked in (I couldn't distinguish between the solenoid and the valve itself making the click). While the compressor was running, the in and out tubes from the compressor got up to about 170 degrees. The radiator coils stayed room temperature.

Then I switched to heat again, and because I was leaning into the closet with my finger on the solenoid, I realized not only was the solenoid not clicking, but the compressor wasn't kicking in. Then I had a 'duh' moment, a real forehead slapper - when I switched to heat a few times the first time I was trouble-shooting, I wasn't turning the temperature up (you can tell I don't really use the heat function here in Florida). So I turned the temperature up to 99 (since the ambient was 96) and sure enough, the compressor kicked on and it started pumping out heat (impressive in 96 degree heat already). Then I switched it back to cool, and it immediately started pumping out cold - wonderful, really cold - air. I got a 37 degree differential, so there was obviously nothing wrong with this system, besides a stuck reversing valve and it only took one cycle to unstick it (I did do some tapping on it with a plastic screw driver handle). So A64pilot wins the prize for correct diagnosis.

More information on the refrigerant: I contacted Dometic and got a helpful response - they said this unit may or may not have 410 as some units with my model # did have R417 which is a replacement for R-22, and that if I gave them the serial number, he could tell me the refrigerant. So in looking for the serial number, the info plate said right on there R-22, AND the amount - 13oz (I hadn't stuck my head far enough into the closet to find the info plate which was on the back of the plenum chamber).

The Dometic rep also said (when I mentioned what the manual said) that it was "somewhat misleading" and that the unit could be serviced. He did say not to use my gauge manifold on a 410a system if it contained any residue of the old (R22) oil, and of course it has to handle the higher pressure of a 410a system (which mine would have - but luckily I didn't even need to go that far and use my gauge on the R-22 system). I wondered why even a little residue would make a difference and did some research. Found this online:

"R-410A contamination caused by any trace of residual R-22 remaining in the system: If any R-22 and R-410A is mixed in any way, oil clumping will occur which will lead to restrictions and blocking of refrigerant flow through the coils which will result in poor performance, system damage and eventual failure."

and...

"The R22 mineral based oil system is not compatible with the R410A ester oil based system and if cross contaminated will cause the oils to coagulate and could ultimately lead to a system failure."

I just thought that was interesting.