brand new pump and filter slows down after 30 minutes

rhonda2063

Member
Aug 11, 2020
10
matawan nj
Help. We had a hayward sand filter it ran for 30 minutes then slowed down, so we were told to check the impeller (it was clear) change the sand which we did.. Ran the pump and filter all good for 30 minutes then again slow. So we purchased a brand new hayward DE filter and pump, and all new hoses. Ran it for 30 minutes then again it slowed down. Had a pool company come in and vacuum it thought debris maybe the issue. Same thing ran for 30 minutes and slowed down. Does anyone have any ideas. Pool guy added shock and more DE earth and checked water level said all good. he had no idea what could be the issue, said maybe defective pump and filter, we said but same thing happened with the sand filter. thought maybe its the timer and it is slowing down the pump but don't know how to check. Anyone have suggestions.
 

JohnT

Admin
Mod Squad
TFP Expert
Apr 4, 2007
9,876
SW Indiana
Welcome to TFP!

What do you mean by slowing down? Flow reduced? What does the pressure gauge read when it starts and when there is a problem? What does the water look like?
 

BigBadLambo

Member
Mar 31, 2018
13
Raleigh, NC
Put your multivalve into bypass to bypass the filter and see if the pump runs fine without going through the filter. If it runs for hours without a problem, then the problem is not your pump, but your filter. In my case, my filters looked clean, but they weren't. I had to clean them with TSP and now my filter works great.
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
19,862
Bedford, TX
thought maybe its the timer and it is slowing down the pump but don't know how to check.

Rhonda,

Sorry, but your timer would have a better chance of fixing tonight's dinner, then slowing down your pump... :mrgreen:

If the flow back to the pool decreases, it is almost all ways the filter being plugged by algae.. Is your water cloudy or green??

Algae is a chemical problem, not a filter problem.

What kind of pool do you have? What kind of pump and filter?

Thanks,

Jim R.
 

x Wild Bill x

Well-known member
May 5, 2016
72
Rochester, MA
Just to check the obvious, you do not have a variable speed or two speed pump do you? We have a variable speed pump and irregardless of its set running RPM, every time is starts up it runs in "prime mode" which is a set RPM for a set certain time, and then switches to the user set running speed and time. If you have a variable speed or two speed and you have the pump speed set low it may be running a "prime" for 30 minutes then switching to a lower RPM setting which makes you think it slows down. Just a wild guess and I would hope the pool professionals would have figured this out but you never know...
 

rhonda2063

Member
Aug 11, 2020
10
matawan nj
sorry , for the delay. when i say slow down i mean
Welcome to TFP!

What do you mean by slowing down? Flow reduced? What does the pressure gauge read when it starts and when there is a problem? What does the water look like?
when i say slow down i mean the suction and the discharge is not strong. It starts off very strong and then slows down.
 

rhonda2063

Member
Aug 11, 2020
10
matawan nj
Just to check the obvious, you do not have a variable speed or two speed pump do you? We have a variable speed pump and irregardless of its set running RPM, every time is starts up it runs in "prime mode" which is a set RPM for a set certain time, and then switches to the user set running speed and time. If you have a variable speed or two speed and you have the pump speed set low it may be running a "prime" for 30 minutes then switching to a lower RPM setting which makes you think it slows down. Just a wild guess and I would hope the pool professionals would have figured this out but you never know...
it is a single speed pump.
 

rhonda2063

Member
Aug 11, 2020
10
matawan nj
Rhonda,

Sorry, but your timer would have a better chance of fixing tonight's dinner, then slowing down your pump... :mrgreen:

If the flow back to the pool decreases, it is almost all ways the filter being plugged by algae.. Is your water cloudy or green??

Algae is a chemical problem, not a filter problem.

What kind of pool do you have? What kind of pump and filter?

Thanks,

Jim R.
thanks... for the comment. we changed the water it is sparkling clean no algae. it is an above ground 15 x 24 and we replaced the pump and filter with a DE W3C40C928 Hayward.
 

Newdude

Well-known member
Jun 16, 2019
4,833
NY
Hey Rhonda !!
we changed the water it is sparkling clean no algae
We see many a day that say the same. They are usually wrong. Wanna know for sure ??? Perform an Overnight Chlorine Loss Test. It’s easy and free, my 2 favorite things. With that out of the way we can help one way or the other.

Many times people are on the verge of an algae explosion. It grows exponentially and isn’t visible at first. It can stay right there on the fence for quite some time but it always ends in disaster if it isn’t caught. The OCLT will give you the whole story. On the plus side, if it is algae, it’s much easier to kill and rid before it becomes a swamp. TheSLAM Process goes much quicker if you catch the need in time. :)
 

cowboycasey

Gold Supporter
LifeTime Supporter
TFP Guide
Jul 3, 2013
4,577
Fletcher, OK
Did you have a DE filter before? They are the best filter for cleaning your water and will also get filled the fastest out of all of the filters, I suspect it needs to be cleaned and recharged with DE :)
 

Mike1162

Silver Supporter
Jun 13, 2015
722
N Tonawanda, NY
I'm also having trouble imaging any scenario in which the flow could be reduced without effecting the filter pressure. Please confirm the pressure is staying even. Does the filter pressure go to zero when the pump is off?
Are you vacuuming or running the skimmer when this happens?
Is the motor 120 or 240 volts?
Is the motor getting very hot when it happens?
Once flow is reduced if you turn the pump off for a minute does it take another thirty minutes for it to happen again?
 

rhonda2063

Member
Aug 11, 2020
10
matawan nj
I'm also having trouble imaging any scenario in which the flow could be reduced without effecting the filter pressure. Please confirm the pressure is staying even. Does the filter pressure go to zero when the pump is off?
Are you vacuuming or running the skimmer when this happens?
Is the motor 120 or 240 volts?
Is the motor getting very hot when it happens?
Once flow is reduced if you turn the pump off for a minute does it take another thirty minutes for it to happen again?
Hi yes if we turn off the pump and back on it works again strong for 30 minutes. My husband said the pressure goes to zero when off then goes to about 15 then up to maybe 20. The pump doesn’t shut off just the suction and dischargesslows . If we pump the filter it gets better but we can’t pump it every 30 min. This can’t be normal
 

cowboycasey

Gold Supporter
LifeTime Supporter
TFP Guide
Jul 3, 2013
4,577
Fletcher, OK
Yep, your filter and pump are working normally, welcome to DE filter normality.... You have something in your pool that is filling your filter and slowing the flow... It is probably the beginning of your pool trying to turn to green...

When you filter starts out at 15 psi and then goes up to 20 PSI it is time to clean your filter, it does not matter if it is 30 minutes or 12 months.. until your pool water is clear your filter will do this..

SO you had a sand filter and it was doing the same thing, what size sand filter did you have and what size DE filter do you have now?

Does the pump sound change when it starts and after 30 minutes? Does it get quieter? When you clean the filter what comes out, is it dirty water or is it completely clear?
 

rhonda2063

Member
Aug 11, 2020
10
matawan nj
Yep, your filter and pump are working normally, welcome to DE filter normality.... You have something in your pool that is filling your filter and slowing the flow... It is probably the beginning of your pool trying to turn to green...

When you filter starts out at 15 psi and then goes up to 20 PSI it is time to clean your filter, it does not matter if it is 30 minutes or 12 months.. until your pool water is clear your filter will do this..

SO you had a sand filter and it was doing the same thing, what size sand filter did you have and what size DE filter do you have now?

Does the pump sound change when it starts and after 30 minutes? Does it get quieter? When you clean the filter what comes out, is it dirty water or is it completely clear?
Thank you. We bought the house with the pool the sand filter worked great for a few years. Then we dodnt open pool for two years when we opened it this started. We cleaned everything including drain in ng pool changed to de filter and new pump , water tested was spot on chemicals its still crystal clear. The pump sounds the same .were thinking maybe it the electric could it be?
 

Mike1162

Silver Supporter
Jun 13, 2015
722
N Tonawanda, NY
If it was an electrical problem you'd most likely always have low flow. It wouldn't run 30 minutes & then "slow down".
I would disassemble the filter, hose off all the old DE, reassemble, restart & add the correct amount of DE.

This is very important:
What are you testing the pool water with?
What are you chlorinating with & how often?
Do you know the current levels of chlorine & CYA?
 

mas985

TFP Expert
LifeTime Supporter
May 3, 2007
13,825
Pleasanton, CA
Pool Size
20000
Surface
Plaster
Chlorine
Salt Water Generator
Do you have any check valves on the reuturn side of the pump?

If you don't know post a picture of the equipment.
 

rhonda2063

Member
Aug 11, 2020
10
matawan nj
hi then we are at a loss. We bought the water to a local pool store for testing. The water is clean and fully chlorinated. if not electrical then we are really at a loss, since it happened with both filters and both different pumps.
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