SWG on with no flow

[lborne]

I have a CompuPool SWG plumbed in-line with the pool return only and today was the first day we used it. The PB did it this way so that we could not over chlorinate ourselves when in spa mode (single pump runs both pool and spa). But, the SWG is hooked to the pump timer so that it comes on whenever the pump is on. So technically, when I go out to switch into spa mode, I need to turn two valves, turn on the pump, turn on the heat and turn off the SWG. I know that we will forget to turn off the SWG sometimes, and so I did it on purpose to see what happens. The SWG comes on and starts working. I can tell because the cell starts producing bubbles - lots of bubbles. It runs for about 3-5 minutes before it detects the no flow situation and shuts down.

Am I doing any damage to the cell over those 3-5 minutes?

 

[Strannik]

no, but your pipes can melt

depending on current level, cell can generate a lot of heat when producing chlorine, enough to boil the water if it's not running. If the temperature gets too hot, PVC pipes can start melting.

You might need to change your piping so the the water drains from the cell when pump is switched off, that way it should detect no flow straight away.

Can you post photos of your piping?

 

[lborne]

The pipes do drain but take a minute. Even with no water, it still takes a few minutes for it to realize there is no flow.

 

[Strannik]

weird...
might be a flow in their firmware
i'd say if water completely drains within 1 minute, nothing bad should happen

there is no harm in it running when there is no water left in a cell, because it won't be making contact through air anyway.

although i'd raise this issue with their support department to see if that's the intended behaviour

 

[Pool Clown]

Call your PB and tell him to plumb in in correctly. Not only is the way it's plumbed in not correct, But it does not give you the convenience the PB was shooting for. You still have to turn the unit off to use the spa either way. You may as well not have the cell in a dangerous configuration. And i'm going to guess and say that the present installation will void the warranty. It should be in the main line, so whenever the unit has power, there will be water going thru it.

 

[New2Me]

I don't think that this is an application that is suitable for this particular unit. Your return piping to the pool should NOT drain if the valve to the spa is not leaking, and you need a FLOW switch that actually senses water flowing through it, not a water detection sensor. I would contact CompuPool for their recommendation; install a proper flow switch and/or install a contact switch on the pool/spa valve that only supplies power when in pool mode(which would be the easiest one wire fix.)
Good Luck, and Best Wishes!!!