Slowing down Pentair VF pump

Sherryweb1

New member
Jul 24, 2016
3
Sweeny, tx
For the past several months my Pentair VF pump slows down to a trickle (according to my pool side-sprays) after startup in the morning. The Status shows a speed of 1374RPM or close to it. My Intellichem low flow sensor and my Intellichlor low flow sensors are alarming and do not turn on.
So, my current fix is to, every morning, manually turn off my booster pump, my intellichem circuit, and my Intelliflo pump from the Intellitouch panel buttons. Then I switch off the main breaker to the Intellitouch panel, wait a few seconds and switch back on. After some time the panel restarts the VF pump, booster and chlorinator. After restart, the side-sprays return to normal, the flow alarms go away, and the speed indicates 1780 or close to it. Then everything runs fine the entire day. But if I am not home, or forget, the pump is too slow to make the speed switches and the pool turns green.
I have tried several things, such as clean the DE filter, check the skimmers and main drain, redirect each drain valve to ensure good suction, clean the pump strainer. I have even changed the turnover settings from 2/day to 4/day. Nothing seems to work other than a full power-down and restart.
I have noticed that during the morning startup, the pump flow starts high and a lot of air burbs out into the pool. The pump speed then starts to slow down in increments until it reaches 1374rpm. That is when it starts to trickle-flow. The startup (prime) time is around 1 minute, however I have increased the Prime setting to 15 minutes on the panel. I have also changed the VF pump flow setting to 30GPM although that is only for manual starts, which I do not use.
I plan to fix the air burp or vacuum leak as soon as the parts arrive. Small vacuum leak heard at one of the Intellichem clamp tubing connection gaskets. I don't think that the air burp and the slow speed are related, but thought I would mention it. That is the only thing that I can tell that has changed.
Any help determining the slow speed on the VF pump?
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
28,593
Northern NJ
Pool Size
35000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-60
Do a Overnight Chlorine Loss Test. You probably have algae clogging your filter over time.

When you turn off the pump the DE and algae falls to the bottom of the filter. That clears the flow for a while until the algae accumulates on the DE blocking the flow.

Nothing is wrong with your pump.
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
22,854
Bedford, TX
Sherry,

I doubt you have a pump issue at all.. You just have a really dirty filter, compounded by Algae..

Clean your filter and get rid of the algae and you will be back up and running.

Take a good read through our pool school and see how we do that.

Thanks,

Jim R.
 

Sherryweb1

New member
Jul 24, 2016
3
Sweeny, tx
Do a Overnight Chlorine Loss Test. You probably have algae clogging your filter over time.

When you turn off the pump the DE and algae falls to the bottom of the filter. That clears the flow for a while until the algae accumulates on the DE blocking the flow.

Nothing is wrong with your pump.
Thank you Jim and Allen for the quick response!
I cleaned the filter not that long ago and did wash off some brown powder earlier. And the filter pressure was very low if not zero at low flow.
So I took your advice and re-cleaned the filter. The first thing I noticed was I had way too much DE Powder applied to the unit, and a DE build up at the bottom of the filter. At least it was white powder this time. Probably more than double. I was told my measuring scoop was 1/2 pound when in reality when measured a full pound. I have been adding 2x for over 12 years apparently.
Now, having the measured amount of DE Powder, I will see if that fixed my problem. Currently it is running great.
ps. since I can visibly see green, no need to conduct the overnight test according to the instructions. It's not bad, just noticeable.
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
28,593
Northern NJ
Pool Size
35000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-60
.
ps. since I can visibly see green, no need to conduct the overnight test according to the instructions. It's not bad, just noticeable.

Algae can be in even clear water. Algae can begin clogging a filter within hours.

You need to follow the SLAM Process and get your pool to be algae free.
 
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