Return water leaving SWG after filter pump shuts down

[VA2AZ]

Hey, I do not need this forum often, but when I do I get great response.
Had a pool heater installed in December, which included a check valve between heater and SWG.
For whatever reason, hoping to get some suggestions, after the filter pump stops, the water in the salt cell slowly goes down level to the bottom of the cell on the incoming side of the cell. On the return from the cell to the pool, the water is not visible. The cell is empty. There are no signs of a leak above ground and from the new check valve to the final return out of the Cell, nothing was disturbed. On Pinpointleakdetection website they show a card to get to measure the drop in water level over 24 hr period. 1/4 inch is ok, anymore indicates a leak. No rain, no irrigation leaks, no 'drainage' into the pool other than the return.
My water bill matches last years bills from Dec thru April. I do not have auto fill, manually hose it when it gets close to 1 inch in skimmer.
Sounds simple, just do not want to spend $700 to find out I do not have a leak, or I need to stand on the corner and save up my money. Thanks for all that respond.

 

[Jimrahbe]

Bear,

When you shut the pump off, I would expect the water in the cell to go back into the pool.

Maybe I just do not understand, but it seems you are trying to make a problem out of normal operation.

If you have a tab feeder, you need a check valve between the heater and the tab feeder.

If you have just a SWCG, you do not need a check valve as there is nothing 'bad' in the cell that could damage anything.. ever...

Thanks,

Jim R.

 

[proavia]

Sounds like air is getting into the system after the pump shuts down.
This could be on the suction side or the return side.
If on the return side, when pump is on you may or may not see water leaking out.

Post a few pictures of your pool equipmemt pad and plumbing from a few different angles so we can see what you are working with.

My SWG doesn't drain the water out when the pump shuts off.

 

[Jimrahbe]

Bear,

Obviously, how your cell is plumbed would have a lot to do with if it drains or not.

Please show us a couple of pics of your equipment pad.

Thanks,

Jim R.

 

[1poolman1]

Bear,

When you shut the pump off, I would expect the water in the cell to go back into the pool.

Maybe I just do not understand, but it seems you are trying to make a problem out of normal operation.

If you have a tab feeder, you need a check valve between the heater and the tab feeder.

If you have just a SWCG, you do not need a check valve as there is nothing 'bad' in the cell that could damage anything.. ever...

Thanks,

Jim R.

For some reason, SGS, now CMP, systems had a check valve installed to their systems. Its in the instructions. As an installer I always did on those so that if there was ever a warranty issue, (only had one, a leaking cell housing) there could be no, "Your installer did it wrong, sorry." None of the others I have installed, Pentair, Hayward, call for that.

 

[VA2AZ]

Bear,

When you shut the pump off, I would expect the water in the cell to go back into the pool.

Maybe I just do not understand, but it seems you are trying to make a problem out of normal operation.

If you have a tab feeder, you need a check valve between the heater and the tab feeder.

If you have just a SWCG, you do not need a check valve as there is nothing 'bad' in the cell that could damage anything.. ever...

Thanks,

Jim R.

Jim, thanks for the reply. Heater manufacturer recommends check valve after the heater and before the SWG. Prior to Heater install, system from filter pump to return after Salt Cell the salt cell was solid water, no bubbles, just water. Now, the cell is empty after about 5 minutes of off time. It cannot go backwards because of the check valve. It seems to me that the system was a sealed system and ALL plumbing was "air" free running or not. BTW I have separate pump/system for cleaning (Paramount Pop ups).

Sounds like air is getting into the system after the pump shuts down.
This could be on the suction side or the return side.
If on the return side, when pump is on you may or may not see water leaking out.

Post a few pictures of your pool equipmemt pad and plumbing from a few different angles so we can see what you are working with.

My SWG doesn't drain the water out when the pump shuts off.

photos posted.

 

[VA2AZ]

Bear,

Obviously, how your cell is plumbed would have a lot to do with if it drains or not.

Please show us a couple of pics of your equipment pad.

Thanks,

Jim R.

photos posted.

 

[Jimrahbe]

Bear,

What specific heater do you have??

Just because there is a check valve does not mean it is working..

Check valves work better when there is pressure trying to push them shut.

My gut says there is just not a problem, I'll wait for the pics.

Thanks,

Jim R.

 

[VA2AZ]

Bear,

When you shut the pump off, I would expect the water in the cell to go back into the pool.

Maybe I just do not understand, but it seems you are trying to make a problem out of normal operation.

If you have a tab feeder, you need a check valve between the heater and the tab feeder.

If you have just a SWCG, you do not need a check valve as there is nothing 'bad' in the cell that could damage anything.. ever...

Thanks,

Jim R.

Jim, Just got off the phone with CMP tech support. Water should stay in the plexiglass cell if the pump is running or not. He said even though there is a flow tab to fire up the fins, there is still electricity going to the fins and could shorten the life of the cell. Typically, the cell is attached to an automated system and starts up 10 minutes after the pump and shuts off 10 min before the pump. I was not told this when the Cell was installed. I have a 2002 power panel with manual timers, and the filter pump, has it's own timer, is wired to one of the timers and the pool cleaning is wired to the other. It will take me awhile to figure the power distro, so in the mean time, a check valve will do.

 

[Oly]

What is the highest point in your filter system? For most it is the top of the filter canister which commonly is where the pressure gauge and air relief valve is installed. When you shut the pump off listen closely for suction sounds and start at the top of your system. It is likely upstream of your cell and may be a loose union, leak at a fitting or missing or dry o-ring.

 

[Jimrahbe]

Bear,

Maybe your cell is different than every other one I have seen, but most cells are hollow tubes with metal fins inside. You see right through them, so what would hold water in them?? Obviously if they are plumbed lower in the system, then water would stay in them, but if they were plumbed higher in the system, then gravity would just drain the water out.

I don't see any pics..

Thanks,

Jim R.

 

[jgofnj]

Bear,

Maybe your cell is different than every other one I have seen, but most cells are hollow tubes with metal fins inside. You see right through them, so what would hold water in them?? Obviously if they are plumbed lower in the system, then water would stay in them, but if they were plumbed higher in the system, then gravity would just drain the water out.

I don't see any pics..

Thanks,

Jim R.

Pictures were added to the original post.

 

[VA2AZ]

Bear,

What specific heater do you have??

Just because there is a check valve does not mean it is working..

Check valves work better when there is pressure trying to push them shut.

My gut says there is just not a problem, I'll wait for the pics.

Thanks,

Jim R.

Jim, Gulfstream Heat Pump Heater. It is obvious that the check valve is working because after the cell empties of water, the water level is at the bottom of the cell on the inlet. The water is well below the level of the cell on the outlet side.

 

[VA2AZ]

What is the highest point in your filter system? For most it is the top of the filter canister which commonly is where the pressure gauge and air relief valve is installed. When you shut the pump off listen closely for suction sounds and start at the top of your system. It is likely upstream of your cell and may be a loose union, leak at a fitting or missing or dry o-ring.

Oly, Highest point is the filter cap with pressure guage. No gurgling or suction sounds. Because I have the opportunity to live in Great State 48 a surface water leak is extremely easy to identify. My equipment area is very very dry. All joints, fittings and unions that are above ground are also very dry. No runs, no drips, no errors. Since there is water in the inlet pipe to the salt cell, the check valve is keeping water and air from traveling backwards or forwards.

Bear,

Maybe your cell is different than every other one I have seen, but most cells are hollow tubes with metal fins inside. You see right through them, so what would hold water in them?? Obviously if they are plumbed lower in the system, then water would stay in them, but if they were plumbed higher in the system, then gravity would just drain the water out.

I don't see any pics..

Thanks,

Jim R.

Jim, the pics are in a .pdf file. I just checked. Click on the pdf file, select pdf viewer and they will come up in a separate window.

 

[proavia]

First place I'd look is the O-rings in or near the SWG.

Open it all up, clean the O-rings and all mating surfaces, check for bad or deformed O-rings, then relube the O-rings with silicone based pool lube and reinstall. Don't over-tighten any of the fittings - hand tight should be tight enough.

If that doesn't lead to a solution, look at the check valve O-rings and the O-rings at the heater unions.

With the pool suction (skimmer/main drains) and returns (water outlets below the pool water surface - and the pool plumbing being full of water when the pump is running and immediately after pump rurns off..... the plumbing should hold all that water - unless there is an air leak somewhere.

If it were normal for the SWG to have the water in it replaced with air, the filter would drain down as well.

 

[proavia]

Because I have the opportunity to live in Great State 48 a surface water leak is extremely easy to identify.

Except when we are extremely dry (75% of the year).
Then a small run or drip can evaporate before it's noticeable.

 

[Jimrahbe]

after the cell empties of water, the water level is at the bottom of the cell on the inlet. The water is well below the level of the cell on the outlet side.

Bear,

Thanks for the pics...

I would assume that air has to be entering the cell, or through the check valve lid, this air allows the water on the output side of the cell to "leak" back into the pool.

When the pump is off, the cell should not have any power, so it should not matter. I guess my point is that you are not losing any water and the cell will fill back up as soon as the pump starts. What problem are we trying to fix?

I see everyone's point that in a perfect system no air would get in and nothing would drain back into the pool.

And.. the pump manual actually says that if you are using a SWCG you must install a check valve. Unfortunately this is a sad reflection on what the company knows about how a salt cell works.. But, if this were my heater, I too would (reluctently) add a check valve.

Thanks,

Jim R.

 

[VA2AZ]

When you shut the pump off, I would expect the water in the cell to go back into the pool.

Maybe I just do not understand, but it seems you are trying to make a problem out of normal operation.

Jim, Prior to installing the heater, the SWG cell stayed full of water. Nothing has changed from the SWG to the pool, except a possible leak in the return plumbing. As you can tell by the photos, the check valve is below the cell, and it is holding water because the water stays in the inlet pipe. The water goes down below the cell and it is replaced with air. CMP tech support says the 'fins' are still active even when the filter motor is off. The control panel for the SWG is not on any type of timer, unless I manually turn the SWG off.
My goal is to have the cell stay full of water, prior to the heater/check valve install. This was my normal operation prior to the install.

 

[VA2AZ]

Except when we are extremely dry (75% of the year).
Then a small run or drip can evaporate before it's noticeable.

Gene, with the system running, I paper towel all joints and nothing shows up. Once again, water is not escaping via the check valve inlet, it is full of water. The return pipe to the pool, after the cell is below the cell and pipe. This did not occur prior to heater install. As far as the O'Ring for the 'lid' to the SWG, manual and Tech support say NOT to lubricate that O'Ring.

 

[proavia]

There have been reports over the years of air getting into the return side of the system when the pump is off without there being a water leak when the system is running. Those reports are far and few between.

When you turn the system off, do you hear any guggling or any other noises?
How long after shutdown does the air show in the SWG?

Run the system for avout 30 minutes to purte all air out of the system. Shut the system down and immediately try putting shaving cream on the SWG connection points - both sides of each union nut. If you see an area where the shaving cream gets sucked in, that is close to the location of the air entering the system.

If you don't find a leak close to the SWG, move on to the next closest fitting.

Are the SWG O-rings a silicone tyoe material or rubber?
I have never heard of not lubing the O-rings/seals.