SWG "fact" check from pool guy

[skidad]

Hi all,

I installed an RJ45+ this summer to automate my chlorine needs after much reading and confidence gathering from this forum. I followed the instructions and my system worked great all summer. While I was out over the weekend, my guy who winterized my pool for me came and closed my pool down (mostly because he's insured and I had a pipe leak when the pool was built), anyway he made a comment to one of my teenagers, to have your dad call me, the SWG is to close to the heater and is going to cause corrosion of the heater elements.

Can you help me understand if this is true? Is it based on the old tab feeder thoughts? I just don't understand how the water flowing out of the heater, into the SWG can "cause corrosion" of the heater, it's a one way road. Pics attached for clarity.

 

[SJPoe]

It looks like the flow is through the heater, and then the SWG right ? If so, not sure what you have to worry about.
Even if it was the other way around, the change in pH across the SWG is minimal, and only really occurs when the water is flowing...
You could install a check valve, but there really isn't much point

 

[Jimrahbe]

Dad,

It may be too close to the heater, but it will not cause any kind of heater corrosion.

If it were a chlorine tablet feeder, he would be correct.. But that does not apply to a SWCG because when the cell is off, it is off, there is nothing that can go backwards into the heater.

Thanks,

Jim R.

 

[ajw22]

Can you help me understand if this is true?

Not true.

Is it based on the old tab feeder thoughts?

Yes, and it is the acid in the Trichlor tablets that kill the heater. Not the chlorine.

I just don't understand how the water flowing out of the heater, into the SWG can "cause corrosion" of the heater, it's a one way road.

With a tab feeder the one way road can backflow when the pump is off and the tablets and acid are still dissolving.

Your SWG should be wired so the SWG is powered off when your pump is off. There will be no chlorine in the cell that can backflow into the pump.

So its the acid, not the chlorine, and the SWG has none. And the cell should not generate chlorine when the pump is off.

 

[skidad]

Thank you all, my builder had installed a tablet feeder right in he same location as I put the SWG. Which is a big reason I installed the SWG there, it made sense. The SWG is after the heater for sure. This is very helpful, and yes, I wired my SWG into the same circuit as the pump, so no pump == no SWG. I felt very confident in what I did and you all are confirming, I'm not looking to argue with the guy, just wanted to get some validation before we have the conversation

 

[ajw22]

All that said, we do recommend having a heater bypass that uses a check valve...

Heater Bypass - Further Reading

www.troublefreepool.com