Heater Flow Switch
Most pool heaters, gas or heat pump, use a pressure switch to determine if there is water flow and the heater should run. There are conditions when the pressure switch will sense pressure in the heater pipes but there is no flow, such as when:
- the heater is bypassed and pressure is trapped in the pipes
- the heater is installed below the waterline allowing the pressure switch to be closed from static pressure with no flow
