Green flow switch light even when pump is off


New member
Aug 1, 2017
The trouble started with a red flow switch light on my Intellichlor IC-40 even when there was good flow (a problem noted by others on this board). I tried bending the flow switch stalk and then the light was always green, even when the pump was off. This worked to produce chlorine, but I didn't want to leave it like that. I bought a replacement switch from Optimum Pool Technologies, which installed very easily, but again the light was always green, even when the pump is off. Ive contacted the seller of the switch for a replacement, but I wonder if I am missing something?


Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
Laughlin, NV
If the SWCG is powered without the pump running the SWCG can explode. Power it down now and use liquid chlorine until you fix this issue.

Welcome to the forum.


Gold Supporter
TFP Guide
Jul 21, 2013
Northern NJ
I wonder if I am missing something?
Buy a Pentair replacement flow switch.

As Marty said, power off the SWG until the flow switch is repaired.

Pentair Manuals say:

WARNING:CHLORINE GAS BUILDUP CAN OCCUR WITH IMPROPER WIRING: To reduce the risk of personal injury the IntelliChlor® Salt Chlorine Generator (SCG) Power Center must be installed on and wirded to the load side of the time clock, electronically controlled switch, or relay load side, so that it will receive power only when the pool pump is on. Otherwise, dangerous chlorine gas buildup can occur. The IECG should never be energized when the pool pump is OFF and water is not flowing through the unit. [7]

The risk is ...



Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
Bedford, TX

You seem to have two problems.. From a safety point of view, your cell should not have any lights at all when the pump is off. This problem is not the flow switch.. It is that your salt system wired wrong. The IntelliChlor transformer should NEVER get power when the pump is off.

Do you have an EasyTouch or do you have an external power center for your cell?

As far as the light being green when the pump is off and there is no flow, that does sound like a flow switch problem, but not as likely since you installed a new one. It is possible of course..

If this were my system, I would check to make sure that the color coded wires are matched in your recent installation.

I would then shut if off and remove the new flow switch. Then test with an ohm meter to confirm that it shows an open, between the Red and Black wires, when not pressed against the stalk.. And a short (zero ohms) when pressed against the stalk..


Jim R.