I am working on a packaged geo that conditions an indoor pool area and heats the pool water. The pool water is heated at a thin plate heat exchanger. What we know to be a desuperheater circuit is what the geo circulates through this thin plate heat exchanger. The thermostat control for pool water goes through a tecmark 3900 series pressure switch on the pool water plumbing circuit. My pressure switch is not activating at this time. Does anyone know what pressure the pool side loop should be? A separate pool company takes care of the pool side pump and plumbing. I don't want to tell homeowner to have their pool company come out until i can verify if the switch is legitimately open circuit due to low pressure. Thanks.