Bought a second hand ionics system few months ago and the control valve has gone wonky. What I did notice is that the pressure switch is wired in aswell. Now call me dumb but I was under the impression If you have a controller you don’t wire the pressure switch into the circuit aswell.
I was under the impression that Ionics used a flow PWM regulator that doesn't have a calibration option (dead ending) so uses the pumps pressure switch to control this function.
The only 2 controllers that have Dead End calibration were the Varistream and Spring Controllers.
The Varistream manufacturers advised to take the pressure switch out of the equation. Spring controllers suggested it be left in place as another fail safe. Their controller is programmed to recognise the action of the pressure switch. However they also say that its not imperative that the pressure switch is included in the circuit.
If the controller is playing up then it could be the pressure switch in the pump. But with a flow controller only, you need a pressure switch.
Hopefully someone who has an Ionics system can clarify the pressure switch issue.