Appreciate the feedback. Learning from every comment given, and it seems like everyone else I talked to said "no leak sealant". So at least I am able to know what NOT to do.

Stock up now.

Dan it does little good to stock up as the equipment is no longer made. The end of the road began on Dec. 31, 2024.... if you can't get equipment the refrigerant is obsolete.

Time as it were. Tick Tock. Average National Expected life of an AC system is 15 years. There is more to this equation than just refrigerant alone.

What do you suggest when I have service come out here to deal with the situation?

First you have to find a competent HVAC company who has the equipment and experience to find refrigerant leaks. See if there are companies who will make an honest effort to do a repair instead of replacing equipment.

If I have to live with every 2-3 years someone coming in and filling me up more freon ($400-$500 for service call), I guess I could live with it.

That is a bad strategy and also illegal. HVAC companies cannot add refrigerant to equipment with a known leak. I have to think that is the rule in New York. Leaks get worse over time. It is highly doubtful if a leak is present the proper refrigerant level would last 2-3 years.

I am interested in the diagnosis of the problem and what you decided to do. Please post back with an update.

I have someone coming next week. Will update.

I found the right person (I feel), who came over and after an inspection feels that the "leak" (if there is a one) is the coils of the LG header(s). He did find that the valves on the compressor itself were not as tight as "it should be". My 410A charge was down to about 40%. We agreed not to touch anything, added 410A and we shall see where things go.

In his experience of many years, he feels that if soldiering was done to connect the line sets, they almost never spring a leak.

So, that's my update. Thank you everyone for chiming in.

He did find that the valves on the compressor itself were not as tight as "it should be". My 410A charge was down to about 40%. We agreed not to touch anything, added 410A and we shall see where things go.

Yes, this is one way of many. The con with mini split problems of this nature is the equipment models change so frequently that the head, coils or whatever is not able to be located or due to flare type compression fittings in the lineset themselves are leaking and in some situations the lineset sweats and for whatever reason the lineset pits with corrosion leaks. It could be either or both places.

So the rule of thumb if you can do it, is to add refrigerant tighten service connections make sure they are sealed as best as possible. Then wait... if the unit charge lasts a month or two? probably time for the obvious. If the charge lasts a year, the end is coming.

Nothing illegal in doing this as a method to get to the bottom of it. Typically legalities of refrigerant usage starts with systems holding 50 lbs or more of refrigerant. I doubt this mini split holds even 20 lbs of refrigerant, maybe not even 10 lbs. total charge.

State level could impose restrictions as a California imposed problem, the rest of the so called blue states just follow everything California does.

If the charge lasts a year you may be able to string it along for a few years if you're fortunate. A leak sealer at that point may not be a bad idea. If the refrigerant charge lasts a month or two, I doubt a leak sealer will do much at that point.

I stand corrected about the EPA not allowing the adding R410a refrigerant to residential equipment with a known leak. New York may have it's rules on refrigerants. New York was the first state to ban gas stoves in new construction starting in 2026. Other bans are likely to occur in the future.

...after an inspection feels that the "leak" (if there is a one) is the coils of the LG header(s). He did find that the valves on the compressor itself were not as tight as "it should be". My 410A charge was down to about 40%. We agreed not to touch anything, added 410A and we shall see where things go.

Was there an attempt to locate the leak with a leak detector? That would be good information to have in my opinion.

"after an inspection feels that the "leak" (if there is a one) is the coils of the LG header(s). "

90+% of all leaks are at the evaporator coil.