Pool Pump Lost Pressure after a Vacuum to Waste Session

qnuck

New member
Jul 25, 2020
4
Canada
Hi everyone,

I am a new pool owner and was able to get the pump running a few weeks ago but now it is acting up. Here is the behavior:

1 - After a vacuum to waste session, it stopped returning to the pool and now won't prime
2 - Currently if I am on Waste mode it has GOOD suction and flow on either the Skimmer or Main Drain side
3 - On Rinse or Backwash it also flows just fine
4 - Recirculate or Filter has NO return to the pool side
5 - When trying to prime, I fill the basket with water from a hose and the water level goes down every time. I don't know where it's going / if this is normal when trying to prime or if I just need to run it longer (than 20 minutes)
6 - Even when the pump DID work there would be a large knocking / shaking when I presume the water filled the return lines (heater shakes all over for a second) ... not sure if this is normal

Any thoughts / suggestions are much appreciated! I am trying to rescue a neglected pool. After years of being covered/unused it was full of black water, which became a green swamp. Fortunately I was able to restore it to clear water and don't want to go backwards if the filter stops running.

Thank you!!
 

zea3

Mod Squad
TFP Expert
LifeTime Supporter
Jul 10, 2009
12,643
Houston, Texas
Hi wecome to TFP! How high is the water level in the pool? Is it at least 1/2 way up the skimmer opening? Did you open the air bleed on the filter? Please fill out your signature with information about your pool and equipment. It will help us answer your questions.
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
19,126
Bedford, TX
q,

Did you suck up a bunch of leaves?

Based upon your list of behaviors, it sounds to me that your multiport valve is plugged up or maybe has a bad spider gasket.

I'd pop the MVP top off and see what you can find.

Thanks,

Jim R.
 

qnuck

New member
Jul 25, 2020
4
Canada
Thank you for your reply. The level is almost half way up the skimmer but I was using the main drain to try to prime it. I will fill it further just in case.

I will update the signature as soon as I figure out how. It is a in ground pool with a Triton II Sand Filter. I believe it is an old Sta Rite pump with Centurion motor
 

qnuck

New member
Jul 25, 2020
4
Canada
q,

Did you suck up a bunch of leaves?

Based upon your list of behaviors, it sounds to me that your multiport valve is plugged up or maybe has a bad spider gasket.

I'd pop the MVP top off and see what you can find.

Thanks,

Jim R.
I think that would be very possible. I'll look and see how to take the top off.

A week ago I did lose some water to waste when I was on recirculate which I found weird so it is possible there is something off with the multiport valve
 

JamesW

TFP Expert
Mar 2, 2011
20,724
Do you have a picture of the equipment?

Sounds like you plugged up the heater with debris.

Do you have a salt cell?

What does the pressure on the filter go up to?

What exact pump do you have?
 

qnuck

New member
Jul 25, 2020
4
Canada
I do not have a salt cell.

It is possible the heater is plugged, I do not know. How would I check the heater for a plug?

The heater is not working at the moment by the way. It is not turning on and the front cover is warped, so I need to open all the panels and look at it.

I tried for a couple hours today and got it to work, so now the filter is working and recirculate. I'm afraid that whatever happened is going to happen again when I backwash the filter in 1-2 weeks.

Still not sure why it decided to work. What I did before working was open up the pump cover and there was a little bit of sand debris at the bottom. I removed that and also used a hose with JET to flush both the suction side and impeller side. It then worked so I have no clue if I dislodged something by using the jet setting on the hose.

Filter: Pentair Triton II
Pump: Sta-Rite "Century Centurion"
Pentair Chlorinator Model #320

IMG_9069.jpg
 

JamesW

TFP Expert
Mar 2, 2011
20,724
Possibly a clog in the heater or chlorinator.

Make sure that the pump basket is clean and seated correctly.

Maybe check the impeller to see if it's jammed up.