Pentair variable speed pump problem

[bregobob]

Yep, I have the same problem as This thread with a newly purchased Pentair VST. Very troublesome because my system is very tight with no evidence of air leak at any level, no bubbles at the pool surface, or pool loss of water level. New pump. new DE filter set running on 1.5 inch diameter copper pipe. It was suggested by Pentair that the newly engineered variable pump requires 2 inch plumbing to return adequate flow. While that may be the case, my single stage Stay-Rite 1.0 HP has been running the system for years with a full bowl, fantastic flow and considerable turbulence at the pool surface. I will not dig up my pool pad and replace all the pipe with 2 inch PVC just because of a new pump design. The problem of low water level and return flow to the pump chamber seems to be less (longer to manifest) before adding DE. It is almost like the pump cannot handle a pressure change when DE is added. Others say that it is normal for that pump to operate at lower RPM and present less water in the chamber. I, like you concern myself that the pump may run dry in my absence. If a low bowl is normal at 3450 RPM, then I accept that.
I can pipe 2 inch above ground to prove my point or, I can rebuild the bearings of my old single stage. The variable speed energy saving argument has no merit if I have to run twice as long per day to achieve the same results. I challenge Pentair, or anyone else to prove me wrong as all I want to do is restore my pool to it's previous performance. I would be interested as to what else you have learned about the problem.

Edited by Moderator -- Rule 4

 

[Jimrahbe]

Bob,

The idea that 1.5" pipe will not work for a 3 HP IntelliFlo is not telling the whole story.. I suspect that there might be some issues if you are trying to run full speed all the time, but most people never need to run their IntelliFlo at full speed.

I did not go back and read the old thread as we want to hear the problem directly from you.

Show us some pics of your equipment pad...

Is your pump controlled by an automation system, or is it a standalone pump?

What speed(s) do you run and for how long?

Air leaks are often not obvious, and most pools have some small air leaks.. Since, unlike a water leak, they don't leave a trail, they are often not noticed.

When an IntelliFlo is running at low RPMs there is almost always a bubble under the pump lid. This is almost never an issue and the bubble may change in size a little during the day, but it should not just keep getting bigger and bigger.

When the bubble keeps increasing in size, it is often caused by a small air leak.. Either at the pump lid gasket, or at a bad O-Ring at a Jandy valve, or sometime due to broken PVC fittings.. etc.

I have never heard of the problem being an actual pump issue, it is almost always an equipment pad or install issue.

I am not at all interested in what you think of Pentair or Jandy or Hayward. Our goal is to not provide a place for ranting, but rather a place where you tell us the problem, and we try to see if we can come up with a fix for the problem.

Thanks,

Jim R.

 

[bregobob]

Bob,

The idea that 1.5" pipe will not work for a 3 HP IntelliFlo is not telling the whole story.. I suspect that there might be some issues if you are trying to run full speed all the time, but most people never need to run their IntelliFlo at full speed.

I did not go back and read the old thread as we want to hear the problem directly from you.

Show us some pics of your equipment pad...

Is your pump controlled by an automation system, or is it a standalone pump?

What speed(s) do you run and for how long?

Air leaks are often not obvious, and most pools have some small air leaks.. Since, unlike a water leak, they don't leave a trail, they are often not noticed.

When an IntelliFlo is running at low RPMs there is almost always a bubble under the pump lid. This is almost never an issue and the bubble may change in size a little during the day, but it should not just keep getting bigger and bigger.

When the bubble keeps increasing in size, it is often caused by a small air leak.. Either at the pump lid gasket, or at a bad O-Ring at a Jandy valve, or sometime due to broken PVC fittings.. etc.

I have never heard of the problem being an actual pump issue, it is almost always an equipment pad or install issue.

I am not at all interested in what you think of Pentair or Jandy or Hayward. Our goal is to not provide a place for ranting, but rather a place where you tell us the problem, and we try to see if we can come up with a fix for the problem.

Thanks,increasing aitr space

Jim R.

Jim
Thanks for responding to my post. I certainly have no time for ranting. You are correct that there are numerous causes for air space in the VST. I have gone through all of them. The only thing I have not done is order a pool leak detection service which I will probably have to do. I totally agree with you that these types of problems almost always do not involve the pump. Having said that, if you always assume an air leak somewhere else in the system you risk overlooking the pump as the culprit. I just spent an enormous amount of money on this pump. So far, I found a huge gap between the motor adaptor plate and the pump housing. The upper housing bolts were 3/4 turn loose and the lower bolts were about a half turn loose fresh out of FACTORY PACKAGING. When the bolts are tightened, I see surface to surface contact at the housing bolt sites, but a whopping 0.032 arching gap on the centerline of the closure. Yes, there is a seal there so I really do not think this is the source of my leak, but it could be.. This is a very appropriate time to question PENTAIR'S QC. so others avoid chasing their time clock on a routine install. I will rebuild my single stage and put it back in operation on the same system. If it performs as well as it did before I lost the bearings on my old pump motor, there is something wrong with the VST pump design. While I will continually look for solutions using the new Pentair pump, it is returning about a third of the water to the pool as did the single stage. Bob

 

[bregobob]

Bob,

The idea that 1.5" pipe will not work for a 3 HP IntelliFlo is not telling the whole story.. I suspect that there might be some issues if you are trying to run full speed all the time, but most people never need to run their IntelliFlo at full speed.

I did not go back and read the old thread as we want to hear the problem directly from you.

Show us some pics of your equipment pad...

Is your pump controlled by an automation system, or is it a standalone pump?

What speed(s) do you run and for how long?

Air leaks are often not obvious, and most pools have some small air leaks.. Since, unlike a water leak, they don't leave a trail, they are often not noticed.

When an IntelliFlo is running at low RPMs there is almost always a bubble under the pump lid. This is almost never an issue and the bubble may change in size a little during the day, but it should not just keep getting bigger and bigger.

When the bubble keeps increasing in size, it is often caused by a small air leak.. Either at the pump lid gasket, or at a bad O-Ring at a Jandy valve, or sometime due to broken PVC fittings.. etc.

I have never heard of the problem being an actual pump issue, it is almost always an equipment pad or install issue.

I am not at all interested in what you think of Pentair or Jandy or Hayward. Our goal is to not provide a place for ranting, but rather a place where you tell us the problem, and we try to see if we can come up with a fix for the problem.

Thanks,

Jim R.

Jim Thanks for your response.

 

[Newdude]

While I will continually look for solutions using the new Pentair pump, it is returning about a third of the water to the pool as did the single stage

While as a rule that people can get a larger pump that is capable of running slower, there has to be an exception to the rule. I'm sorry you appear to be said exception.

Keep us posted.

The upper housing bolts were 3/4 turn loose and the lower bolts were about a half turn loose fresh out of FACTORY PACKAGING

QC has tanked pretty much everywhere these days. In the rush to get *any* product out there during the shortages, the manufacturers proved that the items would fly off the shelves regardless of QC or price increases. I don't see either changing anytime soon, and again to be fair, it's bloody everything. Vehicles, appliances, pool robots, pool robots, pool robots, etc.

 

[bregobob]

You need to witness the bubbles forming to rule out everything at the pad before the pump. If it's leaking you can soak the unions/valves/fittings with a hose and the bubbles will stop if you hit the right spot.

Thanks. I will try that. The only ftgs before the pump are the disconnect ftg and the male threaded adapter PVC screwed into the pump housing. As soon as I return home I can supply some pics and elaborate further as to what the pump has done. Bob

 

[bregobob]

Does any know the best technique to detect and clear an obstruction on the suction side?

 

[Newdude]

A 'drain king' / bladder will likely show a full obstruction if you can't push water through the pipe with it, but it likely won't show the extent of a partial obstruction.

Start with the easiest fix, the weir doors. Cycle them manually real well to prove they aren't sticking or stuck with debris.

 

[bregobob]

While as a rule that people can get a larger pump that is capable of running slower, there has to be an exception to the rule. I'm sorry you appear to be said exception.

Keep us posted.



QC has tanked pretty much everywhere these days. In the rush to get *any* product out there during the shortages, the manufacturers proved that the items would fly off the shelves regardless of QC or price increases. I don't see either changing anytime soon, and again to be fair, it's bloody everything. Vehicles, appliances, pool robots, pool robots, pool robots, etc.

I could not agree more with your assessment of the supply world. I am concerned American manufacturing standards like ASTM are lost. This will take us off forum topic however

 

[bregobob]

While as a rule that people can get a larger pump that is capable of running slower, there has to be an exception to the rule. I'm sorry you appear to be said exception.

Keep us posted.



QC has tanked pretty much everywhere these days. In the rush to get *any* product out there during the shortages, the manufacturers proved that the items would fly off the shelves regardless of QC or price increases. I don't see either changing anytime soon, and again to be fair, it's bloody everything. Vehicles, appliances, pool robots, pool robots, pool robots, etc.

Yep, what ever happened to American manufacturing practices like ASTM?

 

[bregobob]

A 'drain king' / bladder will likely show a full obstruction if you can't push water through the pipe with it, but it likely won't show the extent of a partial obstruction.

Start with the easiest fix, the weir doors. Cycle them manually real well to prove they aren't sticking or stuck with debris.

I am not using weir doors

 

[Jimrahbe]

I am not using weir doors

Bob,

That does no make any sense, but... not having a weir door should have nothing to do with your pump issue..

Jim R.

 

[Newdude]

not having a weir door should have nothing to do with your pump issue

I mentioned the weirs as a possible cause for air in the pump basket. Not having them obviously rules stuck weirs out.