Could be r22 or 410a, I've had this issue on several boats in the marina this week, mostly dirty filters over the evaporator, the others were weak cooling water flow.

When first turning it on bring it down in increments as stated. There is also a setting that will force a defrost mode every so often. Refer to the manual. Had the same issue on our Outlaw for a long time.

Mark

I had the same problem (ice) the day after i had a burnt smell and not so much cold air. I stopped the a/c and looked what could have melted and found nothing visually. Anyone knows what i should look for?

Residential units have pounds of refrigerant and when it goes low they freeze up. Your typical marine unit has very little refrigerant and a critical charge meaning it has to be very a specific amount with no room for error. If it develops a leak the refrigerant is gone very quickly and the unit stops working . I don`t have that much experience with marine units but systems with a critical charge will not freeze up when a leak develops they will just stop working.
So if your unit is freezing up its most likely NOT related to refrigerant levels.

In those units freezing up is related to air flow mostly. Insufficient return or supply would be my guess.or the obvious dirty filters.
Keeping the fan "on" instead of 'auto' may bandaid the situation by defrosting the coil between cycles. My last unit stopped when the thermostat was satisfied and that unit used to freeze up.
My current unit (better make) keeps the fan running (does not freeze up) but also has a much stronger blower.

This is the second boat I have had this problem and they have been extremely susceptible to freezing if conditions are not perfect. Was hoping someone had come up with a higher volume fan or a secondary fan kit that solved the problem. Cooling water flow is not my issue nor freon level but they can compound the problem

Don't turn to heat right away, that will damage compressor you gotta let system equal out first in off position.... Same after running boat let oil settle before using it.

Icing over is low freon or lack of airflow, make sure return air is sufficient also can cause freezing up, all the units I see are R22 can't just go buy it, find hvac guy to do it they don't hold but maybe 14oz

CLEAN your condenser fins out well!

If it's freezing up that's a GOOD thing most likely unless it's overcharged. You just need it to work like a proper heat exchanger and FLOW some hot air thru it for it to cool.

I literally just cleaned mine today and WOW what a difference. It was freezing up also and I had to turn the temp slightly warmer, let the fan run without the compressor on, to defrost it often.

I reached around the condenser and scrapped a layer of muddy goo, almost like dryer lint, with my finger tips. Then soaked it in simple green and sprayed out with a garden hose. I also cleaned the entire compartment that it's mounted in and the intake filter. I plan on putting a piece of screen door over the condenser so it's easier to remove and clean. I have no clue if that's the proper way but WOW did it work.

My A/C blows colder and the fan blows 5 times harder then it has in 5 years we have owned our cruiser. I feel stupid for not realizing this was part of the maintainence sooner.

I am a HVAC tech. I work on commercial and industrial a/c and refrigeration units.

First it's a critical charge, so charging them is a pain do to the lose when you take the gauge off. Some may not even have service ports. If your freezing up with a system that has less then a pound of refrigerant in it, it's not the charge.

Second, clean the evaporator coil. The coil everyone is talking about is the evaporator coil. The condenser is the hot coil and in the a/c mode it's the outside coil. You need heat transfer, that being said any dirt on that coil is blocking that and killing your airflow and capacity.

While you are cleaning the evaporator coil you may want to find out what type of condenser you have. Is it air or water cooled. Either way that should be cleaned to. This will help it work easier, better, and last longer.
If you need more airflow and cleaned the evaporator coil already, try cleaning the fan blades. As they get dirty they move less air.

Good luck with it, if you need anything else you can p.m. me and I will help to the best of my ability.

There is a setting on the control unit you can also set that will allow the unit to auto deforost for 1,2 or 3 minutes an hour. This essentially does the same thing as the heat mode with out interaction.

In the past I had the issue, thought it was a bit low on freeon, but just needed a good cleaning.

The vector series self contained units will certainly freeze the evap coil with a low charge or faulty thermostat.