Preventing SWCG from backflowing into heater

strategy400

Well-known member
Jun 6, 2013
159
Southern California
Pool Size
40
Surface
Plaster
Chlorine
Liquid Chlorine
Will a check valve stop the chlorine from eating my heater? I have this now, the cell is just above the white flow indicator. I've been using automation to turn off the SWCG 1/2 hour before the pump stops.
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I'm considering inserting a check valve to prevent chlorine water from flowing back to the heater. Excuse my mspaint skills., it's the black thing. I'd like elevate the pipe above the cell but that seems like too many 90s.
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A SWG will not cause cause damage to a heater, so no check valve is necessary. Instruction manuals will often refer to check valves being required for chlorinators. The type of chlorinators referred to are trichlor tablet chlorinators which can create a very acidic mix that can damage heater components. That's not something to worry about with a SWG.
 
You would likely be better served by installing a heater bypass.
With the heater bypassed, you should be able to run the pump at a lower RPM and still move the same amount of water and satisfy the SWG flow switch at that lower RPM as well.

Is the SWG wired so that is does not receive power when the pump is off?

Update your signature with SWG info and test kit info.
 
400,

The idea that chlorine is what 'eats' heaters is just a myth... Sigh!!!

It is low pH, and does not come from a SWCG, but from tablets which have acid in them.. This sludge from tablet feeder will run backwards into the heater and destroy it..

If you do not have a tablet feeder, then you do not need a check valve.

Thanks,

Jim R.