I have a Carrier chiller, 30HL series. Now i have no info on the unit at this time, i know i should but i have a few questions. The chiller is 3 yrs old and is installed in a hot deck cold system. Now this chiller has been working fine all summer but just the other day after we fixed the 3 way valve the system tripped on T 133 and T 134 (low ref pressure Circ A and B). Now my question is did the alarms occur because of the 3 way valve? This 3 way valve is tied into a EMS and opens and closes the valve to the cold deck depending on demand for cooling. The system has been operating all summer with the 3 way valve disabled so they would shut the chilled water pump off if the building got too cold. It just seems a bit fishy given the fact we just replaced the valve. And the kicker is we just took over this account and no one has a clue if the system has ever worked properly. Monday someone will be at the site to check out the problem but i figured i would ask just in case someone else has run into this problem. Sorry for not having any info. Any ideas or suggestions would be a big help.