… the Box is cold, correct ? The sea water temperature where you are is cold, correct ? I am no wizard, but …

I don't think you should see bubbles, froth, or foam several minutes after start-up. In fact, if the system is cold, I think you shouldn't see any bubbles. Only when with a warm box right after startup, should a properly charged system see initial bubbles. I believe the Glass should clear within a short period of time.

I believe the Plate, when starting with a warm box, should frost up within minutes, very quickly be cool / cold to the touch, and a coat of frost within 15-20 minutes or so. With the System not running and gauges connected, do they read about the same ? I think they should, and I think that should be in the 20-40 psi range with cold box & cold water … somewhere between 50-100 psi with a warm plate and warm water. Once you start up, the High side should rise, instantly, to over 100 psi, then slowly & steadily drop to about 100 psi after 30 mins or so. The Low side should drop, instantly as well, to near zero, maybe 0-10 psi within 5-10 minutes, then slowly go to vacuum after about 30 minutes or so and stabilize around -5 psi.

The only time I see anything, froth, bubbles, foam in my Sight Glass is just after start-up of a warm plate / box i.e. > has not been run for some time. If your box is already cold, I think it may be more difficult to diagnose and detect a leak if there is one. When my system is running properly, my Glass is totally clear. But remember, a totally clear Glass also indicates insufficient or no charge. Do you have a digital thermometer ? If so, then shoot the Plate before start up in a few places, then start it up and shoot again, every 10 minutes or so and record, it should steadily drop. There are many other variables of which are way over my head, like a contaminated, or moisture in the Drier, clogged or frozen Valve, etc.

In warm water, my system eventually gets to about 125 psi on the High side and about -5 on the Low, after +/-40 minutes of run time.

I know nothing about these systems, just relaying what I like to see with my system. Kollman is a pro and an excellent source … if he responds ! Good luck, cheers, John