I am trying to set up a service water loop with a central gas heater connected to 16 water use connections on OpenStudio. My EUI was much higher than expected, so I opened the .eso file which said that the Water Use Equipment Cold Water Volume was 0 m3/hour, indicating that no cold water is flowing into the fixtures. Additionally, the Hot Water Volume Flow rate is also really low (in the order of 10^-6 m3/hour). Can someone explain why this is the case?