Return to the Pools & Spas Forum | Post a Follow-Up

 o
Need Advice on Pool Pump

Posted by cnr1089 (My Page) on
Thu, Jul 28, 11 at 16:19

Our pool build as finished at the end of last year. The pool looks and works great (except for one thing).

This summer, the pool was opened in April....Once the pool was salted (we have a salt water generator), I noticed that when the pool pump was run on low speed, I would get "No Flow" and chlorine was not generated.

The pool builder checked it out, but first told me to backwash, etc, to see if it went away. It did, that day, but came back the next day...

I told them again and they said they would check it next time they came out. Next time they came out, they were doing other things, and of course, it did not show No Flow when the pump went to low speed...About an hour later, I got no flow.

Ok, so now it is mid-summer and they finally came out with advanced notice, where I ran at low speed all morning, no flow, of course, again.

This time, after talking with Hayward (this is all hayward equipment), they said that that is just the way things are (there isn't enough flow)....

So, our pool technician (from the same company as our pool builder) said, "Well, you just have to run the pump on full speed longer." I am a little bummed, the whole point is that we ran at full speed for a few hours (filtered all our water through once), then the remainder of the day at low speed, saving me energy....

Anyways, I think based on the design, the distance from the pool that the equipment was, etc, if there wasn't enough flow, they should have installed a Variable Speed pump, rather then the dual speed pump. So far the technician said that because it was a year old pump now, there is no way they would be able to just trade it up and give me credit, because it is used....But of course, I told them about the issue as soon as I noticed it (almost immediately after the pool was fully turned on)....

What should I do? My thought is a variable speed pump would let me get a lower speed that will actually produce enough flow, thus working around this problem. I am not expecting a free lunch here, but if the equipment doesn't work as specified, I am thinking the pool builder should make it right (they designed it, they should have known if there would be enough flow, etc).

Thanks in advance....


Follow-Up Postings:

 o
RE: Need Advice on Pool Pump

Smaller two speeds may not push enough. A larger unit may be called for or a variable speed.

Scott


 o
RE: Need Advice on Pool Pump

cnr1089....I would call Hayward Tech support to see what they have to say.

I suspect the 2 speed has enough flow for the generator....most 2 speeds at low speed deliver around 40-60 gpm for typical head pressures. This is greater than most generators require which is about 30 gpm to work.

When you call Tech support, they will likely ask for the pump model number and filter gage pressure.

If you would like to post this information here, that would help also.

Hope this helps.


 o
RE: Need Advice on Pool Pump

The pool builders called Hayward while they were at my house and went over our system, basically because the pool equipment is above the pool and > 30 feet and we have a Heat Pump (which is about 10 feet away from the other equipment) and Propane heater, that the pump cannot push the water at low speed.

I think the Two Speed pump we have is 2.5 HP (I could be wrong). I can get the exact details tomorrow. I am really trying to figure out if I should push the pool builders to help me out here, since they designed the system, installed it, etc. I think I should, but I don't really have much to stand on, because they will likely just say "Just run at full speed longer." I hate having a very expensive brand new thing that isn't working how it is supposed in the first year!


 o
RE: Need Advice on Pool Pump

A 2.5 HP should have way more than enough at low speed. I have 1/2 HP and even that is enough at low speed. Goldline units don't need much at all for flow rate.

However, it could be an indication of something else going on. Check the flow switch and make sure something didn't get stuck in there.

Also, please post the following.

Pump Model
Filter model
Pump height above/below water level
Pipe diameter
Number of suction runs from pool to pad
Filter pressure on high speed


 o
RE: Need Advice on Pool Pump

I was wrong about the pump, here are my specs:

Hayward NorthStar 2HP (dual speed) pump (I misread the THP as being 2.5, thinking that was the HP pump):

Hayward DE6020 Filter (120GPM)

Looks like 26 Psi? on high:

Here is a picture of my equipment (note, the heat pump is to the far right, on the other side of my air conditioner units):

And here is the pool equipment in relationship to the pool. I would say it is like 30-40 feet away:

Note, the equipment is about 4 feet higher then the top of the pool....


 o
RE: Need Advice on Pool Pump (additional info)

Oh, the pipe diameter (according to the pool guy) is 2". I am not sure how many suctions, but we have a main drain (although it is split in two with two actual drains, I am pretty sure it is just one pipe to the equipment) and two skimmers (not hot tub).


 o
RE: Need Advice on Pool Pump (one more thing)

One last thing...I still get no flow when I do a backwash and clean out the filter basked....although it takes longer after turning the pump down from full speed (I have never timed it, but no flow usually doesn't show up right away when going from full to low speed).


 o
RE: Need Advice on Pool Pump

The pressure is a little high and indicates quite a bit of head loss. I estimate somewhere around 80 GPM with 73' of head on high speed and 40 GPM with 18' of head on low speed. So that should be more than enough flow rate to trip the flow switch.

I would focus on the flow switch. Is any water bypassing the flow switch because you have two heaters?

Also, the flow switch much be installed in the proper direction. Check the arrow on the switch and make sure it is pointed in the correct direction.

A picture of the pad plumbing might help.


 o
RE: Need Advice on Pool Pump

When I see a large DE filter showing me 25 PSI when clean, then there is a substantial blockage of some sort. In this case, I suspect it is the heaters. I am also assuming that the cell has been checked for scale, not an unusual event with a newer plastered pool.

I am assuming the heaters are in series, the gas heater and then the heat pump. The two of them need some plumbing modifications.

I think the best option is to plumb the heaters in parallel with valves set up so you can shut the flow to either, both, or bypass them. I doubt you would use both at the same time so eliminating the unused one or both from the path will help a lot.

I would also add a shortcut valve between each heater's intake and exhaust. This would be used when both heating and high speed are used. Neither heater's water pathway should be asked to take the full brunt of the Northstar's flow at high speed.

I suspect the bigger restriction will be found to be the heat pump.

I don't know if you can automate this fully but it would likely solve this challenge.

Scott


 o
RE: Need Advice on Pool Pump

poolguynj:

I do remember the pool guy talking the hayward guy about doing some sort of bypass of the heaters, etc....

Should I push for them to re-arrange these, rather then push for the Variable Speed pump?

Here are some more pictures of the pad area:




 o
RE: Need Advice on Pool Pump

cnr1089....Thanks for the additional info.

With the reported filter gage pressure, I also suspect too many restrictions between the pump and the pool.

With the choice of a 2 speed pump, clearly, you're energy concious. Energy savings only comes with low speed filtering and optimizing plumbing hydraulics.

In your case, you have the pump that is capable of low speed but unfortunately do not have the optimum hydraulic design.

Getting a variable speed is only a band aid to fix the symptom and will result in higher operating costs due to higher speed operation.

As poolguy recommends....running the heaters in parallel will help significantly. Also, having bypasses for high speed operation is recommended. I think all the heating manufacturers recommend this in their installation manuals.

These plumbing changes will require valving and preferably automation...hopefully your current automation system has the capability of handling the extra automation requirements to make the system work conveniently without having to run to the pad when needed.

Hope this helps.


 o
RE: Need Advice on Pool

cnr...forgot to mention...before going too far...have you had the flow switch checked as mas985 mentions. It would be regrettable to make all the changes mentioned above when the root cause was the switch itself (incorrect orientation, debris, teflon tape debris, bad switch, bad electrical connection, etc.).

Hope this helps.


 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!


Return to the Pools & Spas Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Please review our Rules of Play before posting.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.


Learn more about in-text links on this page here