We get a phone call at work telling us that our glycol temp is too high on our ice rink chiller and it's pulling way low on the suction side. After a lengthy conversation on the phone, we stop by the rink to take a look. We are using the new electronic expansion valves from Sporlan for only the 2nd time, so we are thinking this is the problem. Turns out, the only problem with the valves is the pressure transducers needed an offset, so this wasn't the problem.
Well to make a long story short, after spending an entire morning checking everything out, one of the service guys tell us that they have had a leak in the glycol circuit for a few days. They had been adding water to the glycol to keep the level up. This knocked the freeze point of the glycol to around 19F degrees and we were pumping down to almost -30F. So, we basically froze up the chiller.
Now if we would have known this before we made the site visit, we could have spent the morning doing something constructive.