What does water SW Open mean on my Raypak heater?
What does water SW Open mean on my Raypak heater? The heater will only operate for a short time before it cuts off and displays the message "Water Sw Open." Even if the water flow in the pool intake and return appear normal, it still may be possible the flow could be restricted enough to not allow the pressure switch to close and therefore stop the heater from firing. What does it mean when my pool heater says water SW open? Since you stated that you're not getting a good return to the pool, your most likely getting insufficient water...