Is this normal ?

[Blue Fin]

I'm helping out my wife's friend with her 25K vinyl in ground pool that is approximately 8 years old with 2 skimmers, 3 returns, no main drain and 1 1/2" plumbing. She had a Jandy pump that was shot.

So I replaced it with a Hayward VS super pump. Great unit btw. The installation was pretty straight forward and I used 1 1/2" PVC unions on both sides of the pump. Got the pump up and running and noticed that the Praher SM20-2 multi-port valve was leaking to waste. So I swapped out the internal gasket (major PIA as it was glued in) as well as the cover O ring. Lubed everything with a light coat of silicon grease. That fixed that problem. I also cleaned the Jandy DEL48 DE filter that was a real mess. Added 5lbs of DE in a slurry. The start up pressure is within spec with the pump running at full speed.

OK so here is the issue(s);

1). It takes forever to purge the air out of the DE filter and it drains down when the pump is shut off. Is this normal because the equipment is above the level of the pool ? I don't see a check valve anywhere in the system. There is a heater but no auto-chlorinator. I also hear what seems to be a gurgling noise inside the multi-port valve.

2). Can't seem to purge some air out of the pump basket. I believe this may suggest a leak somewhere on the suction side.

Thanks in advance for your suggestions.

 

[zea3]

It sounds like there is a suction leak. Drizzles some water slowly over the pipe joints and connections while the pump is running and watch to see if any water is sucked in. Also check that the plug on the pump strainer pot is tight, and that the pot strainer lid fits well and the o-ring is lubed. Also make sure the water is high enough in the pool and there is no whirlpool action in the skimmer while the pump is on.

If fixing the leak does not solve the problem of the filter draining when off then you may need to install a check valve.

 

[Blue Fin]

Thanks for the prompt reply. I'll check the input connection to the pump to make sure it's tight. This is where I suspect there may be a suction leak. When the DE filter drains down I don't notice any water spilling out anywhere. It seems to drain out into the plumbing system (i.i; back into the pool).

 

[harleysilo]

Man you really are helping her out. That's a lot of work.

I don't think either of what you describe is "normal". I would think air would have to be getting into the filter somehow, otherwise it shouldn't drain. Mine doesn't drain out and i have no check-valve (different brands but still). I'm assuming you aren't seeing any leaking anywhere, that would make it too easy. Air in pump basket is symptom of suction side leak, did you lube the gasket when you re-installed the pump lid?

 

[Blue Fin]

Yes, I lubed the gasket and the o-rings on the unions. Only thing I can think of is maybe I need to tighten up the threaded adaptor going into the pump. I noticed a bit of leaking on the discharge side and I loosened the union and tightened up the threaded pvc adaptor 1/2 turn. That corrected that issue. So I'm thinking the same needs to be done on the inlet side. And I did wrap the threads with teflon tape 2 turns.

As far as the leak down, that's correct, I don't see any water coming out. Just hear it running out though the system.

 

[Richard320]

Yes, I lubed the gasket and the o-rings on the unions. Only thing I can think of is maybe I need to tighten up the threaded adaptor going into the pump. I noticed a bit of leaking on the discharge side and I loosened the union and tightened up the threaded pvc adaptor 1/2 turn. That corrected that issue. So I'm thinking the same needs to be done on the inlet side.

As far as the leak down, that's correct, I don't see any water coming out. Just hear it running out though the system.

It could be something as small and simple as the winterizing drain plug on the pump strainer housing.

While it's running, open the air bleed and empty it out. Then try again after a few hours running. If more air has built up, you know there's a suction side leak. If not, you might have just had air trapped in the tank that compresses while the pump's on, and forces the water out when it's off.

 

[woodyp]

How MUCH higher is the pump from the top of the pool? Buddy of mine has one that is like 20 feet away and 3 or 4 feet up a small rise and it has been recommended to him to install a one way valve on the suction side cause that pump won't keep prime when it turns off.

 

[Blue Fin]

Hey thanks for all the replies guys. The inlet to the pump is approximately 18" above the pool level. I was there earlier and checking the system. I tightened the threaded intake coupler and that didn't have any effect. One thing, actually2 things I noticed are the Jandy valve on the inlet side was installed backwards and the cap on the side for the lubricator is missing. Not sure it the valve being installed reverse would cause this issue. I put my finger over the port on the side of the valve to cover it and that didn't have any noticeable immediate effect. I realize it takes a few minutes for the air to clear out of the strainer but didn't really notice any suction on my finger when I removed it.

Also the first 2 returns are blowing bubbles. I can't seem to bleed the air completely out of the DE filter and there is a noticeable gurgling sound in the multi-port valve.

 

[Blue Fin]

UPDATE

The gray Jandy valve was positioned with the cover reverse. In other words, the input was on the pump side not the suction side.

I removed the 8 screws and reversed the cap position 180°. When correctly installed, the valve in the "open" position blocks the grease port and any possible air suction that might occur through it.

That is the "IN" marked on the valve is on the suction side, not the pump side.

In my friend's case with a suction side leak I believe this corrected the issue. Not to mention the grease cap is missing from the valve. Best thing IMO would be to replace the entire valve with a new "black" one.

No more bubbles in the cap of the strainer basket cover

Hope this helps someone in the future.

Best to all and thanks much for those who responded.