Pentair Pump Motor Replacement

hgiljr · Apr 1, 2022

Good afternoon everyone. I have a pentair superflow model 340043, two speed pump. I recently replaced the bearings and seals on it. Lately I am seeing the inpool vacuum having difficulty to move around. Once I close the skimmer valve and just leave the vacuum side open, it has enough suction to move around. I did use the vacuum flow meter and all looks fine, but mainly works once I leave vacuum side open. If I open the skimmer valve a bit, it moves but not as much and just stays around same section.

So I am guessing, its the motor not having enough power as it did. Next up I am guessing is to replace the motor, but #1 having issues to find a replacement two speed and #2 not sure if to stay with the 1.5hp rating for the new motor or upgrade to 2hp. I mention the upgrade because I do have a long distance from the pool pump to the pool, about 45ft. I have always see some of the last jets in the pool return, not have enough flow. Questions are:
1. Would upgrading to 2hp on new motor make a difference?
2. Any recommendations of where I can find a replacement motor?
3. Does it even sound as a pump problem or might be something else?

Thanks again

1poolman1 · Apr 1, 2022

If it worked before you changed the bearings it should work the same afterward, motors just turn. Something else would be the issue. Changing the motor to 2hp (not recommended) would only bring about a change if you also changed the impeller and any other internal parts that may be needed to accommodate the impeller. Its not like putting more horsepower in a vehicle. Due to Federal laws that went into effect in July last year, it is also an illegal modification. It is no longer legal to even manufacture single or 2-speed motors in that horsepower for pool use.

A SuperFlow is a medium-head pump and your system was already pushing it to the limit of its ability with 90+ feet of pipe (45' both ways plus filter, above-ground plumbing, and whatever else the water has to go through, like your suction cleaner), even at 1.5hp. You can research what a medium and high head pump are. You would be better off upgrading to a pump with more capability to handle your system like an IntellFlow or IntelliPro. If your builder install the SuperFlow it is because that pump cost hundreds less than a high-head pump like the others mentioned, even in 2-speed configuration. Most pool owners never find out the difference until the system gets some age on it and they start experiencing issues like yours.

hgiljr · Apr 1, 2022

Thank you for response. Going back to issue on hand, when I close all valves and just leave open the vacuum valve, vacuum works as it should. Wouldn’t this be a caused by the motor not having enough power? It worked just fine till bearings were replaced. I also went ahead and removed the cartridge filter and ran pool without filter to see if it helped the vacuum while skimmer valve was open and same results. I retested the suction using the measuring spring like measuring device that came with the vacuum and it’s sits between maximum and minimum suction. Could it be something with the vacuum itself? Thanks

1poolman1 · Apr 1, 2022

Pool-pump motors such as yours run at a constant speed, regardless of horsepower. For 2-speed motors it is either 3450 or 1725 rpm. Increase the motor horsepower without changing the impeller and it will still only move the same amount of water as the speeds will still be the same. If your 1.5hp impeller can move 60 gpm with a 1.5 hp motor turning full speed it will move the same amount of water with a 2hp motor as it will still turn at that same speed. If a small person can fill and move 2 five gallon buckets of water a minute, a larger, stronger person moving 2 five gallon buckets a minute will do the same amount of work but have an easier time doing it. That is how pumps work. Changing the bearings has no effect on that except that the motor will run a little easier with new bearings.
Yes, it could be a problem with the cleaner. You don't say what brand, model, or age. As they wear the internal parts don't function as well and they can slow down.
Another thing that can be the cause is the "O" ring that is supposed to be on the diffuser (part 16 in a parts diagram). If it is missing the pump will not have the suction it normally would and you will see the issue you are having. Since you had your pump apart it may have been broken and fallen off and not noticed or removed because the pump wouldn't go back together with it in place.
Your impeller could be clogged, especially if your basket is broken, or very worn. These are most of the issues I see in the field.

hgiljr · Apr 2, 2022

1poolman1 said:
Pool-pump motors such as yours run at a constant speed, regardless of horsepower. For 2-speed motors it is either 3450 or 1725 rpm. Increase the motor horsepower without changing the impeller and it will still only move the same amount of water as the speeds will still be the same. If your 1.5hp impeller can move 60 gpm with a 1.5 hp motor turning full speed it will move the same amount of water with a 2hp motor as it will still turn at that same speed. If a small person can fill and move 2 five gallon buckets of water a minute, a larger, stronger person moving 2 five gallon buckets a minute will do the same amount of work but have an easier time doing it. That is how pumps work. Changing the bearings has no effect on that except that the motor will run a little easier with new bearings.
Yes, it could be a problem with the cleaner. You don't say what brand, model, or age. As they wear the internal parts don't function as well and they can slow down.
Another thing that can be the cause is the "O" ring that is supposed to be on the diffuser (part 16 in a parts diagram). If it is missing the pump will not have the suction it normally would and you will see the issue you are having. Since you had your pump apart it may have been broken and fallen off and not noticed or removed because the pump wouldn't go back together with it in place.
Your impeller could be clogged, especially if your basket is broken, or very worn. These are most of the issues I see in the field.

As for the O ring, it was replaced with a new one. So I know it’s in there. Vacuum is 2 years old. Pentair kreepy krauly great white. I can see the rubber skirt is fine. I will open it up and see if I can find anything broken. As for the clogged impeller, it wasn’t when apart and basket is not cracked. Is there a way to check if clogged without taking it apart?

cowboycasey · Apr 2, 2022

If you are going to change your pump and filter grab a VS 3 hp pump.. Best of all worlds.. when you want to run the cleaner set it at 2000 rpm when you do not set it at 900 rpm and save massive money...

setsailsoon · Apr 2, 2022

hgiljr said:
Thank you for response. Going back to issue on hand, when I close all valves and just leave open the vacuum valve, vacuum works as it should. Wouldn’t this be a caused by the motor not having enough power? It worked just fine till bearings were replaced. I also went ahead and removed the cartridge filter and ran pool without filter to see if it helped the vacuum while skimmer valve was open and same results. I retested the suction using the measuring spring like measuring device that came with the vacuum and it’s sits between maximum and minimum suction. Could it be something with the vacuum itself? Thanks

H,
Did you replace the bearings because they were making noise or because the vacuum wasn't working right and you thought this might help? If it's the latter I would think you had a problem with the cleaner not the pump. Replacing the bearings and seal should change pump capacity. The suction measuring device seems to indicate your pump is working fine. Do you feel about the same amount of return pressure as before? What kind of in pool vacuum do you have?

Chris

hgiljr · Apr 3, 2022

setsailsoon said:
H,
Did you replace the bearings because they were making noise or because the vacuum wasn't working right and you thought this might help? If it's the latter I would think you had a problem with the cleaner not the pump. Replacing the bearings and seal should change pump capacity. The suction measuring device seems to indicate your pump is working fine. Do you feel about the same amount of return pressure as before? What kind of in pool vacuum do you have?

Chris

I replaced bearings because they were making noise. Vacuum was working just fine before bearings began to make noise. I have a pentair kreepy Krauly great white. I was thinking that if it was something wrong with the vacuum internals, then it shouldn’t work when only the vacuum side valve is open. Would this be an accurate assumption?

setsailsoon · Apr 3, 2022

hgiljr said:
I replaced bearings because they were making noise. Vacuum was working just fine before bearings began to make noise. I have a pentair kreepy Krauly great white. I was thinking that if it was something wrong with the vacuum internals, then it shouldn’t work when only the vacuum side valve is open. Would this be an accurate assumption?

Yes that is probably correct. However it doesn't take much inside the water motor on any suction cleaner to reduce performance and or require more water flow. I would check to be sure you don't have a leaf or something caught in the vanes of the pump. It's pretty easy to do.