SWG Ahead of heater

MouseMan54

Well-known member
May 18, 2016
97
Riverside, CA
I think I know the answer to the question, but I'll ask anyway. Is it an issue to install a SWG ahead of the heater? I'm installing all new equipment (expect for heater) and the optimal place, from a routing perspective would be to install the SWG cell after the filter and before the heater. I will also be installing diverter valves to bypass the heater when not in use and my plan would be to put the flow switch on the bypass so the SWG will have fail safe to only run when pump is running and flow is trough the bypass. My alternative is to put the cell in bypass pipe but this creates a tighter pad and a few more bends in the plumbing. My first thought was this would be bad because of highly chlorinated water going into the heater and potentially the gasses from the cell but the bypass addresses this. Plus, the water from the cell is only a few ( 5 or 7) ppm higher that my target FC anyway.

Am I missing something else? Advice?
 

proavia

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TFP Guide
Feb 6, 2015
1,514
Chandler AZ
but the bypass addresses this
Until someone leaves a valve in the wrong position. Then the SWG is running and sending that water thru the heater or the SWG isn't producing chlorine at all. And maybe that incorrect valve setting goes un-noticed for days/weeks....

Putting it after the heater is the best location - even if that means adding a few more fittings and piping. In the grand scheme of things, those extra few fittings will not adversely affect your flow.
 

MouseMan54

Well-known member
May 18, 2016
97
Riverside, CA
That one did cross my mind. I do test regular so I *should* notice if the cell weren't running for a few days. I'm just tying to save some room on the pad for access and save some room in the pipes incase I need to modify or repair in the future. (i.e. cut into. Most of my fittings are pretty close as is.)

So accounting for human error, what are the implications of running the cell and having that water go through the heater, assuming the heater will be off. The heater is manual, so I would defiantly turn off the cell if I were running the heater. Is the chlorine level from the cell a serious concern? Under normal conditions, even the water coming off the cell would be a lower chlorine PPM than if someone were doing a SLAM without a heater bypass. If I were SLAMing I would defiantly bypass the heater.

And then, assuming double human error, (1)running the cell not on bypass, (2) with the heater on, compounded with the failure of the flow switch, does the water coming off the cell create a dangerous situation in a running heater?
 

Richard320

TFP Expert
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Jan 6, 2010
22,059
San Dimas, CA (LA County)
The extra plumbing to do the installation safely will probably have less effect on flow and cost less than a bunch of bypass valves.

You're assuming you'll live there forever. What happens if three years from now you decide to sell and some inspector notes the improper installation? Then the buyer wants it fixed right, and you just want to close the deal. Or you have someone house sit. You can explain things and write it all down, but that's no guarantee he/she won't fire up the heat and have a swim party and forget to do something.

Just do it right.

If it didn't matter where it was placed or how it was oriented, the manufacturers wouldn't include directions for placement.
 

MouseMan54

Well-known member
May 18, 2016
97
Riverside, CA
Thanks for the reply. Those are additional things to thing about for sure. Just bought the house and currently spending a lot of money on remodel and and granny flat for mom. Sale is a ways off but your point is well taken.

I'm not intending to seem like I'm disregarding advice or pushing to do it the way I proposed. Just wanting to understand the concerns and risk factors. You are correct. The manufactures recommend it a certain way for a reason. I'm the kind of person that wants to understand those reasons.

If anyone can share insight into what the problems may be, I'd appreciate it.

The cost was not a concern in my my reason for considering doing it ahead of the heater. I've already bought the bypass valves and installed them. I will do that either which way. It was really in an effort to best arrange the pad, have access to things to maintain, and in the future, if needed be able to repair by cutting into the pipes and having room for new fittings.

Again, I do want to do things right, which is why I'm asking the questions. I just like to know why the right way is the right way. Plumbing and mechanics I'm pretty set with, but chemistry and physics of what happens to when you send that SWG water into the heater are what I'm trying to understand.
 
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jblizzle

Mod Squad
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May 19, 2010
43,217
Tucson, AZ
How about hydrogen gas accumulation inside of the heater from the swg. That just seems like a bad idea :)
 

MouseMan54

Well-known member
May 18, 2016
97
Riverside, CA
OK. Now as I keep thinking about it I think I may have another problem. If I put the SWG in the bypass section, it will be fully isolated in a closed setctio of pipe when in "heater mode". While it should not be running and the flow switch will be in the same section as a fail safe to ensure it's not running with no flow... in the multiple failure scenario it would be isolated an potentially cause an explosion.

From the picture, would anyone consider installing it in the noted location? Better yet, any ideas on how to make that install safe? I know I could abandon the heater bypass idea, but I've already plumbed that in and would waste the cost of the valves, etc. I know I mentioned earlier cost wasn't a primary concern, but I hate wasting!!

My reason to build in the heater bypass was to isolate during regular pool operations, eliminating the addition flow resistance from pushing through the heater. And in the event the heater fails or springs a leak, I can isolate it incase I can't get it repaired/replaced right away.

I'm I over thinking the whole heater bypass?

Pool Diagram.jpg
 

jblizzle

Mod Squad
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May 19, 2010
43,217
Tucson, AZ
Weird, the picture does not show up ... unless I go in to Edit your post ... @Leebo ?

Anyway. Just put the SWG between the pool and last bypass valve. Obviously I do not know what your pad actually looks like, but it has to be possible.
 

MouseMan54

Well-known member
May 18, 2016
97
Riverside, CA
Anyway. Just put the SWG between the pool and last bypass valve. Obviously I do not know what your pad actually looks like, but it has to be possible.
Thanks for the input. That location is a challenge as well as there's not a lot of pipe there. I'd have to build a loop. I need to look at it again when I get home and see what springs to mind. I'm thinking the potential to have it isolated and explode is a no go.
 

jblizzle

Mod Squad
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LifeTime Supporter
May 19, 2010
43,217
Tucson, AZ
I would agree that an explosion would be frowned upon.

Post up a picture and maybe we can help you think outside the box.
 

sgoosman

Member
Sep 12, 2018
21
Boonton NJ
I suspect this is not a good idea. Valve failures mechanical or human can result in a situation of chlorine and hydrogen enter or even build in the heater which will lead to premature equipment death or explosion. Even if a heater bypass is installed, I do not see fitting a check valve, SWG cell and 2 valves between the inlet and outlet heater ports.

If space is limited you'll need to build vertically. Circupool sells a kit:
1559697894897.png

or you can easily build your own. I am space challenged but could easily fit the SWG as you can see:

104908

check valve is out of site if your curious. Other items to be aware, check your pool heater to ensure your heat exchanger is cupro nickel or titanium (heat pump) as salt and chlorine can do a job on copper. I also do not see check valve in your drawing which is necessary to prevent back flow SWG products into the heater.

Regards,

Scott
 

jblizzle

Mod Squad
TFP Expert
LifeTime Supporter
May 19, 2010
43,217
Tucson, AZ
There is no real logical need for a check valve between the heater and the SWG. But, I know all the manuals still call for them. I think it is a hold over from the manuals for Trichlor feeders which do need the check valve to protect the copper in the heater from the acidic water from the tablets.
 

proavia

LifeTime Supporter
TFP Guide
Feb 6, 2015
1,514
Chandler AZ
@MouseMan54 - pictures of you equipment pad from a few different angles may allow us give you a few suggestions. Right now we're just guessing. The only constant advice here is that the SWG should be placed after the heater and heater bypass.
 

MouseMan54

Well-known member
May 18, 2016
97
Riverside, CA
Thank you all for the continued input. I'll get some pics of the pad in it's current state, which is a work on progress. I'm at a pause right now as I glued on one of my cell unions without putting the threaded collar on the pipe first :mad: so I'm waiting on the replacement to arrive.

I think we've answered the where the cell needs to go question and shifted to plumbing questions, so I'm going to start a new thread there on post the pictures there, etc. I also want to get thoughts on using flexible PVC. New thread here.
 
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