practically zero pressure at filter


  #1  
Old 07-17-16, 01:35 PM
H
Member
Thread Starter
Join Date: Jan 2004
Location: United States
Posts: 1,198
Received 0 Votes on 0 Posts
practically zero pressure at filter

in-ground pool with very old Anthony Apollo filter VA-52 and about 6 year old Hayward Super II pump. With fresh charge of DE pressure is about 7 psi. I shocked pool and pressure went up to about 20 so I changed DE. The pressure continued to rise next day after a party and at night it was back up to about 20 so I was planning on changing DE next day. Started pump next day and the pressure was maybe 2 psi. I shut pump off and on few times and opened a bleeder on top of tank to try and clear debris. Still very low pressure. Took gauge off and no debris found. Checked usual places for low pressure-blocked skimmer-no, pump basket full-no. Fished for debris in impellar-nothing found. Took one way valve off suction line and blew air backwards through lines-nothing came out skimmer but air. The pump comes up on prime and basket is full of water and pump sounds fine, but pressure gauge very low. When open valve, the water shooting out top doesn't seem to have usual pressure so I don't think just gauge issue but trying to rig up something to check that. I replaced DE but no change. Just took grids out and was hoping to find big hole in one of them but have not. Did not take them off rod yet but nothing visible. Pool has debris on bottom, can't tell if just dirt-had 13 kids in pool for 3 hours for party!, or DE? Called hayward and they said not pump if I fished around and didn't find anything. Could impellar be blocked partially? Hayward said no. I tried fishing with wire but couldn't really get it to go into vanes of impellar. Thoughts?
 
  #2  
Old 07-17-16, 01:49 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 61,857
Received 1,480 Votes on 1,368 Posts
It doesn't sound like a pump issue.
Does your multi valve have an auxiliary circulation or direct drain position ?
 
  #3  
Old 07-17-16, 02:01 PM
H
Member
Thread Starter
Join Date: Jan 2004
Location: United States
Posts: 1,198
Received 0 Votes on 0 Posts
no, I only have a push-pull valve.

edit:bad O-rings on the push pull valve could create a bypass situation?
 

Last edited by hammerash; 07-17-16 at 02:29 PM.
  #4  
Old 07-19-16, 04:01 PM
H
Member
Thread Starter
Join Date: Jan 2004
Location: United States
Posts: 1,198
Received 0 Votes on 0 Posts
OK, so I can't find any tears in any of the grid panels. No holes in any of the plastic parts between panels or plastic elbow that connects to the metal pipe inside tank. No cracks in welds of the metal pipe inside. No visible exterior leaks in piping. Gauge tested and works. put filter back together and turned on. Zero pressure on gauge, and when open valve on top the water doesn't even shoot out past the filter (8" or so). Unless anyone has any other ideas I think I have to pull pump apart to see impeller. It is only 6 bolts and it won't damage the seal. I think there is just rubber O-ring and hopefully I don't damage it. Other ideas???
 
  #5  
Old 07-19-16, 08:06 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 61,857
Received 1,480 Votes on 1,368 Posts
Not the type of problem I'd expect with a six year old Hayward Super Pump. If it primes quickly then it doesn't indicate an impeller problem but anything is possible.

I don't have much more to add.

As an aside..... I have a 40+ year old inground Sylvan cement pool. The original Hayward pump lasted approx 25 years. The replacement is a Super II and is still going strong.

At one time I had a pressure problem. I narrowed it down to the deep end suction line. A Fisher Price wooden toy had been sucked down the skimmer and was caught in the underground skimmer/drain Tee. Compressed air blew by it just fine. I ended up using high pressure water to blow from the filter back to the pool to dislodge it.
 
  #6  
Old 07-21-16, 01:47 PM
H
Member
Thread Starter
Join Date: Jan 2004
Location: United States
Posts: 1,198
Received 0 Votes on 0 Posts
This is Anthony/Sylvan pool too. I am not original owner. Pool built 30+years ago-maybe 40. When we moved in, in 1999, it had original pumps/motors! I have since replaced them both once.

I took pump apart and found nothing. I do notice that the suction is not as great as it usually is. I am going to look for air leaks in above ground lines. Then I may try to do what you did with water back through system. But it would seem odd that anything there since the skimmer basket is in place and main drain doesn't work anymore and is blocked off.
 
  #7  
Old 07-21-16, 10:23 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 61,857
Received 1,480 Votes on 1,368 Posts
If you had air leaks in the suction line to the pump..... you'd have air bubbles coming out the return.


Crazy stuff happens. Last year my pool was losing water and by diagnosing the problem I determined it was one of the return lines. This year..... not losing any water. Go figure.
 
  #8  
Old 07-21-16, 10:57 PM
H
Member
Thread Starter
Join Date: Jan 2004
Location: United States
Posts: 1,198
Received 0 Votes on 0 Posts
I always have had some bubbles in return. But I pressure tested the suctions side about 2 years ago and it held pressure for several hours with no drop. Like you said, crazy stuff happens. Noticed that the one way valve right before the pump doesn't open up fully when pump on-it has clear window so I can see it. It CAN open, but doesn't. so I guess the pump is not sucking hard enough to fully open it? I put dishwashing bubbles around all fitting from the one way to pump but didn't see anything unusual. also put it around the two pieces of pump where it separates to check impeller and didn't see anything there either.

PJmax, any advice on my other thread in AC section?
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: