I've added a test to Verbal Alarms that will notify when the PSL chiller is "alarming," which most likely means the chiller's water level is low. This is being added on top of the already existing DIAG_MAIN notification for the same event. When the H1:PSL-LASER_CHILLER1_ALARM channel flips to 1, Verbal Alarms will say "Check PSL chiller," then wait four hours before saying it again if the alarm channel has flipped again since then. The reasoning behind this is that the chiller can run for a while (unsure of exactly how long, but past examples have shown the alarm running for up to almost 24 hours) before it will actually turn off, taking the NPRO and amplifiers down with it.
If operators receive this warning, they can relay the message to anyone on the PSL team or refill the reservoir themselves if on a weekend, making sure to note how much water was added.