Over the weekend Tony noticed that the CO2Y chiller flow was dropping - alog74563. He added 4.5L at the time so a leak was suspected. Today, Camilla and I checked on the table and inside the chiller for any signs of a leak, but found nothing. We refilled the chiller and will keep an extra eye on in the coming weeks, but we don't want to swap it out just yet.

We've seen this mysterious loss of water before before (example: alog68356), but we have yet to completely explain it. our two working theories have been:

1. Trapped air bubbles escaping. Especially after a chiller swap or some other event that could put air into the system, trapped air bubbles could escape (burp) causing more water to go into the lines and a drop in the reservoir.
2. The wire mesh diffuser slips out of place slightly and the water then splashes out of the fill port. There is no retaining system on the diffuser, it's just a friction fit with water pushing against it, so it will dislodge itself from time to time. The fill port cover has a small piece of plastic to help hold it in place, but it has also knocked the diffuser out of place in the past. It splashes and drips down right next to the chiller fan, so it dries very quickly, and thus leaves little evidence.

Since we haven't done much with the CO2Y chiller recently, we suspect that #2 was our cause here. Corey had checked on the chillers on the past Thursday Nov 30 (alog74499), so it's possible that the diffuser was dislodged at some point after that and starting splashing out and drying before making a noticeable puddle. When the level got low enough it might have started affecting the flow, though it's not supposed to.

Inside the chiller there are plenty of spots that show signs of a leak; corrosion, sediment, etc. The problem is that we don't know which ones might be new. I'll add some pictures here for chiller S/N:617 so we can maybe tell, but this chiller in particular has many spots already, making it harder to differentiate even with pictures.