Pool and Spa
Questions about Pool Repair? Ask an Expert Online.
can you first tell me if the flow switch is actually making contact?
The flow switch will look something like this
You need to know if this switch is bad. Follow the wires from flow switch onto circuit board and where it plugs in you need to jump out the pins that it plugs onto, this will make the board think the switch is closed and allow power to go to the heater. You also need to be sure the filters are new or at least been cleaned. Low flow of water can cause the heater to shut down.