Water coming out of booster pump line even when pump is off

tnthudson

LifeTime Supporter
Mar 31, 2008
328
Central VA
#1
OK now for my weakest knowledge in pool maintenance...plumbing and equipment. We have a booster pump for our Pentair Legend Platinum vac, and it works great (plenty of power, etc.). This is our third season with the pool, and last year I noticed that water would come out of the booster pump fitting into the pool (the hole where we attach the robot to the wall), as if the pump were still running, even when the pump was off. It started out slow, but this year it is more noticeable, as if we have a 3rd return.
I guess a valve or something is going bad? The booster pump is hooked into our plumbing at the end of the system (after the heat pump, SWG, etc.)...it was put in by our PB so I'm sure it's according to Pentair's instructions, but this can't be good that water is 'pumping' out of the fitting, even when the pump is off? I'm sure it did not do this when it was first installed.
 

Titanium

LifeTime Supporter
Jun 26, 2007
441
SF Bay Area
#2
I have a Polaris 380 and the booster pump is piped in right after the pool/spa return valve. I always have some water coming through the Polaris 380 line when the booster pump is off and the filter pump is on. Since I always leave the Polaris in the pool, I normally don't notice it. When I pull the Polaris out of the water to empty the filter bag is when I normally notice this "bonus" flow - the Polaris has water coming out of all of the various places that it normally does, just at a much reduced flow.

The only thing in my system which would stop or reduce this "bonus" flow is the impeller of the booster pump itself. And I don't see any reason why the booster pump impeller would completely stop this flow.

I'm not sure why you would notice a difference now as compared to several years ago.

Titanium
 

ktdave

LifeTime Supporter
May 8, 2007
888
Katy, TX
#3
The way our systems is plumbed, the "socket" for the Legend is just another return except that the booster pump is piped into it. In other words, it will always have the same flow as the other returns until the booster pump is turned on.
 

tnthudson

LifeTime Supporter
Mar 31, 2008
328
Central VA
#4
hmmmm....I'll take a closer look at it, you would think that it would just be another return, basically. I just thought I remembered a slight flow when I unhooked the vac. in the past, but now you can see the water move across the pool...
thanks, I'll take another gander :shock:
 

Belldiver

Well-known member
Sep 7, 2007
344
Lafayette, Louisiana
#5
I believe a pressure side cleaner with booster pump is supposed to have it's own isolated return to plug into. The booster is not supposed to feed the entire return system, just that one single supply. The return eyeball sockets look the same, but should be plumbed independently.
 

stevenbrla

LifeTime Supporter
May 11, 2007
237
Baton Rouge, LA
#8
I think the "booster" pump is supposed to be plumbed within the return system, rather than independently... as (mine) is not self-priming, therefore it needs the primary pump to keep it filled (with actual flow... which flows into the pool when the booster pump is not on.)

I recall seeing in the Instructions that the pump is not self-priming. I've even had to bump up my 4x160 to make sure there was enough flow to keep my little booster from not cavitating.

so... when the booster pump isn't on, its just another return line. If the flow through yours has actually increased, perhaps your pump has a higher output for some reason (new pump?), or the flow through your other returns has been blocked/reduced, therefore causing more flow through your booster return.

Belldiver... check it out! How's it going over there?

just my 2 cents (worth less though?)

Steve
 

Belldiver

Well-known member
Sep 7, 2007
344
Lafayette, Louisiana
#9
stevenbrla said:
I think the "booster" pump is supposed to be plumbed within the return system, rather than independently... as (mine) is not self-priming, therefore it needs the primary pump to keep it filled (with actual flow... which flows into the pool when the booster pump is not on.)
Steve,

Yes, the booster must be fed by the main filter pump, but the output should be one single output not connected to any of your other returns. Water may flow into the pool through that return too when the filter pump is on, but not at the same rate as your primary returns.

...and I'm shooting for July 24th for plaster and fill. I'm still offshore for the next two weeks. Everything else is pretty much ready. Just a couple small details to complete when I get home.

Jim
 

stevenbrla

LifeTime Supporter
May 11, 2007
237
Baton Rouge, LA
#10
Belldiver said:
stevenbrla said:
I think the "booster" pump is supposed to be plumbed within the return system, rather than independently... as (mine) is not self-priming, therefore it needs the primary pump to keep it filled (with actual flow... which flows into the pool when the booster pump is not on.)
Steve,

Yes, the booster must be fed by the main filter pump, but the output should be one single output not connected to any of your other returns. Water may flow into the pool through that return too when the filter pump is on, but not at the same rate as your primary returns.

...and I'm shooting for July 24th for plaster and fill. I'm still offshore for the next two weeks. Everything else is pretty much ready. Just a couple small details to complete when I get home.

Jim
oh, ok, I thought by independent, you meant separate. I would suspect too, that the rate coming out of the booster "return line" would be a little less, as the flow would be somewhat obstructed by the booster pump impeller, but other than that, its as much a return line as any other.

One thing I'd recommend to anyone who hasn't piped up yet, is to put an isolation valve upstream of the booster pump so you can turn it off to service your booster pump (lest you won't be able to run your main pump while servicing... and sometimes servicing may take a few days...). Better yet, if in doubt, put a valve!! I have one return line that doesn't have a ball valve on it, and sure wish it had one (in addition to the automated valve.... yes, eventually I'll squeeze one in there.)

Congrats on your project! You did good. Looking forward to seeing the finished product!

Steve