Filter draining through solar valve

[cactus_LV]

Today I noticed that after the pump turned off my filter drained by getting air through the solar valve. I have a check valve between the pump and filter so the pump did not drain. Is this something I should be concerned about?
Below is my plumbing setup.

 

[1poolman1]

Today I noticed that after the pump turned off my filter drained by getting air through the solar valve. I have a check valve between the pump and filter so the pump did not drain. Is this something I should be concerned about?
Below is my plumbing setup.
View attachment 543192

Not really a concern. Either you have a true solar valve (or a regular valve with a hole drilled in the diverter, sometimes done), or the valve is not completely shutting off the "solar" plumbing.

 

[cactus_LV]

It's a true solar valve with the little check valve on it.

 

[1poolman1]

It's a true solar valve with the little check valve on it.

They can allow air to enter the system as the solar drains or is not in use (the vacuum-relief valve is always open when the solar is off). This will allow the filter to drain as well.

 

[cactus_LV]

As long as the drained filter is not a concern everything is good I guess Thank you!

 

[Kidswimin]

Today I noticed that after the pump turned off my filter drained by getting air through the solar valve. I have a check valve between the pump and filter so the pump did not drain. Is this something I should be concerned about?
Below is my plumbing setup.
View attachment 543192

I believe the check valve should be after the filter, it is on mine anyway.

 

[cactus_LV]

yes ideally it would be after the filter but I didn't have enough space to put it after the filter but before the solar stub.

 

[Dirk]

I have the exact same schematic and solar valve, and my filter does not drain, nor should it. My check is before the filter, too.

I would be concerned with air in the filter after the next start up. It's simple enough to test:
On day one the solar runs and then the pump shuts off and the panels drain and then the filter drains some amount.
On day two, after the pump has started up again and the solar is full of water again, turn the valve on the top of the filter to see if any air bleeds out. If you get water right away, then the filter is refilling with water and I guess that's OK. But if you get some air first, that means the filter is trapping air. How much air could effect the efficiency of your filter.

Whenever I introduce air into my plumbing, like when I clean my pump basket, I bleed my filter after restarting the pump. I don't want any air in it. But after I do, it never collects air again, solar or no solar.

Another simple thing you can try: if the two check valves are of the same brand, try swapping their guts and see if that makes a difference. While you've got them apart, inspect their flappers and springs and o-rings for any issues. They should look and work the same. Confirm they are sealing well and that the spring tension on each are good.

Or try disassembling the solar valve to inspect the drain-down valve to see if it is closing properly.

You might post some pics of your plumbing. Maybe we can spot something.

My solar pipes leave my pad and then go underground before they reemerge to head to my roof. Which means neither the supply nor return pipes are ever completely cleared of water. I expect that's at least partially why air never makes it from my VR valve to my filter.

 

[cactus_LV]

My solar pipes leave my pad and then go underground before they reemerge to head to my roof. Which means neither the supply nor return pipes are ever completely cleared of water. I expect that's at least partially why air never makes it from my VR valve to my filter.

This is the same for me but I can see the air bubbling through the pipe. (I placed a check valve in the wrong place - removed the flapper - that's how I can see into that pipe) I inspected my check valve and they seem fine - the pump is not draining just the filter. Next step is to disassemble the solar valve to see what's going on. I am also trying to avoid unnecessary air in the system.

 

[1poolman1]

This is the same for me but I can see the air bubbling through the pipe. (I placed a check valve in the wrong place - removed the flapper - that's how I can see into that pipe) I inspected my check valve and they seem fine - the pump is not draining just the filter. Next step is to disassemble the solar valve to see what's going on. I am also trying to avoid unnecessary air in the system.

You will always have air in a pool with solar that is active. When the system shuts off the solar it drains, filling with air. That also allows air into the plumbing which will allow a filter to drain as well. Think about a straw in a glass of water/soda/tea. Put your finger over the opening, lift a column of liquid out. Remove you finger, the straw drains. The vacuum-relief valve at the top of the panel array is your "finger" being removed from the straw. There is no problem with air getting into the system when it is off. It will be purged each time the pump comes back on either through the filter media or the air relief tube in ever filter (except some sand filters).
When pump is running and the solar is off, watch when it turns on and the pool goes crazy with bubbles as the air in the panels is sent to the pool. Its not an issue.
As pools age, the vast majority will experience the filter draining even without solar (mine does). Again, not a problem. Have never found a suction leak, there is no water being pumped out, so I have no idea why it does it. Pump starts, air is purged, all is good.

 

[Dirk]

You will always have air in a pool with solar that is active. When the system shuts off the solar it drains, filling with air. That also allows air into the plumbing which will allow a filter to drain as well. Think about a straw in a glass of water/soda/tea. Put your finger over the opening, lift a column of liquid out. Remove you finger, the straw drains. The vacuum-relief valve at the top of the panel array is your "finger" being removed from the straw. There is no problem with air getting into the system when it is off. It will be purged each time the pump comes back on either through the filter media or the air relief tube in ever filter (except some sand filters).
When pump is running and the solar is off, watch when it turns on and the pool goes crazy with bubbles as the air in the panels is sent to the pool. Its not an issue.
As pools age, the vast majority will experience the filter draining even without solar (mine does). Again, not a problem. Have never found a suction leak, there is no water being pumped out, so I have no idea why it does it. Pump starts, air is purged, all is good.

I'm with ya. My concern is air trapped in the filter, and making it less efficient. When I clean my pump basket, and then restart, I can (and do) purge air out of my filter. I've been assuming a sizable bubble gets trapped at the top of the filter. I use the vent on top of my filter for that (the one that is accessed by turning the filter gauge). When I twist that gauge at other times, I get no air, so I know the filter is full of water. That's whether I'm using solar heater or not. That's why I think my solar panels draining doesn't fill my filter with air.

Anywho, my question/concern is this: will the main pump purge a cartridge filter of any air inside it, regardless of how it got in there? Or can a filter trap an air bubble at the top, that must be manually purged? If the former, than I'm with you, this is a non-issue. But if a filter can trap air, then I would think how it gets in there would be something to try and prevent.

For the OP, I suppose this is easy enough to test, just purge your filter after various scenarios:
(1) when you stop and start the pump without ever engaging solar
(2) after your panels drain and you restart the pump without engaging solar
(3) after your pump starts and solar engages
(4) etc

So basically, If after starting your pump, whether you previously ran solar or not, if your pump always clears out any air trapped in your filter, then 1p is right, it doesn't matter. But if you can catch your filter trapping air, after the pump has run for a while, then I would think this is something to pursue.

 

[1poolman1]

I'm with ya. My concern is air trapped in the filter, and making it less efficient. When I clean my pump basket, and then restart, I can (and do) purge air out of my filter. I've been assuming a sizable bubble gets trapped at the top of the filter. I use the vent on top of my filter for that (the one that is accessed by turning the filter gauge). When I twist that gauge at other times, I get no air, so I know the filter is full of water. That's whether I'm using solar heater or not. That's why I think my solar panels draining doesn't fill my filter with air.

Anywho, my question/concern is this: will the main pump purge a cartridge filter of any air inside it, regardless of how it got in there? Or can a filter trap an air bubble at the top, that must be manually purged? If the former, than I'm with you, this is a non-issue. But if a filter can trap air, then I would think how it gets in there would be something to try and prevent.

For the OP, I suppose this is easy enough to test, just purge your filter after various scenarios:
(1) when you stop and start the pump without ever engaging solar
(2) after your panels drain and you restart the pump without engaging solar
(3) after your pump starts and solar engages
(4) etc

So basically, If after starting your pump, whether you previously ran solar or not, if your pump always clears out any air trapped in your filter, then 1p is right, it doesn't matter. But if you can catch your filter trapping air, after the pump has run for a while, then I would think this is something to pursue.

The number one, most important use of the air relief valve on top of a filter is to release any air that is under compression and trapped in a tank when opening the filter for service. A very clogged air-relief screen and filter media, can, in a very rare set of circumstances, allow air under pressure to remain in the system. Happens more often in a separation tank. It is faster to open the pump, but using the air-relief valve on the tank is good as well.
The air-relief screen is always above the top of the filter media; DE grids or cartridges (and some sand filters), so any air that may get into the system will not affect the area of filtration in the tank.