OKPoolguy

check the actual flow switch in the piping, make sure it is not bent or damaged. When your pump is off, the flow light should be solid. Also how is the flow switch plumbed in your system (horizontal or vertical). The problem your might be having could be since the salt system always thinks the pump is on it will continue to generate chlorine with whatever water is still in there and it will eventually drop the salt reading.

sounds like your box switch over to the metric setting, you say it shows a reading like 3.30, what temperature does it show? Hit the diagnostic button once, it should show the temperature, if it is in the 20's or 30's it is in metric, but to switch it back move the off-auto-super chlorinate button from auto to super chlorinate and it should switch it back to Fahrenheit.

ntx, If you flow light doesn't light up when the pump is off, it will continue to generate chlorine and that will lead to the lower salt readings later since it has used up the salt in the cell without the water moving thru it. How is you flow switch plumbed into your system? It should be horizontal (I have actually seen some put in vertically with the flow going down which is wrong) but you may have to check you switch in the pipe, it will unscrew out and you can check to make sure nothing is jammed in it to make it stay on.

One other option to check is you T-cell setting, hit the diagnostic button until it has a t-number, i.e. t-15. Make sure whatever cell you have on your system is what it has on the box, so if you have a t-15 cell make sure it is set to t-15, to change the setting of it, when it is at the t-number, move the switch (off-auto-super chlorinate switch) from auto to super chlorinate then back to auto. If it was set to a lower cell then what you have it will register the salt as higher than what is in your pool.

well think of the line that leads to you pool cleaner as another pool return outlet, with the pb-4 pump off, you should still have water flow through the cleaner,now with the pb4 pump on, it will take that water and accelerate it to create a higher flow, hence how it may be refer to as a booster pump, and if it has its own breaker you can shut off the pb-4 pump when you don't want the pool cleaner on. Sorry if I'm not making sense with this post, 13 hour days are getting old.

My guess would be since that looks to be a millivolt heater, it has its power provided by the pilot flame. You could do some troubleshooting by temporarily bypassing your pressure switch which what your first picture is. First make sure your pump is on, water flowing through the heater, have the heater off, pull the two wires off the pressure switch, use a piece of wire to jumper those wires together and turn the heater on to see if it will fire up. If it does you can pick up a pressure switch at a local pool store and replace it. If it doesn't fire up. it could be some loose or oxidized wiring that isn't making a solid connection. Please do not run your heater by bypassing the pressure switch as a solution, because the pressure switch is there for safety, it will ensure that water is flowing through you heater to stay lit, if it is bypassed and the pump shuts off, your going to melt down your heater, but then again the high limit switches will kick it off. (unless they have been bypassed, since I've seen that before, along with most other safety switches bypassed)

Usually your pb-4 cleaner pump does not have to be on all the time, but that depends on how its electricity is hooked up, does it have its own switch or breaker to shut it off. You can shut if off if it is separate from the pool's main pump electrically, but always remember that when you run your booster pump, your main pool pump needs to be on, since your main pump will feed it water. As for how the booster pump is plumbed in, please remember water will always flow through it, unless there are shut off valves, the booster pump only accelerates the water that flows through it, to provide the boost in pressure for the pool cleaner.

Are any of these heaters hooked up to an external control unit, i.e. Aqualink RS or any other control panel used with a remote system, if not, it could be the fuse inside the power box of the heater, or a damaged firemans switch. Just my guess...

who needs to shut off the power when working on a motor...

It just doesn't look right...