I was hoping to get a two speed pump that would have less flo and would cure this mystery air leak. My assumption is that I only need high flow when I backwash. I could be wrong
Head
- Thread starter jordangregory
- Start date
Low speed means less suction, so less air drawn in. That isn't a cure. Still, there is some chance it could turn it from a problem to a minor annoyance.
Two speed pumps are typically only turned up to high speed for priming the pump, backwashing, and vacuuming.
Two speed pumps are typically only turned up to high speed for priming the pump, backwashing, and vacuuming.
- May 3, 2007
- 16,875
- Pool Size
- 20000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
You might find that you need high speed for your skimmer to work properly. You will certainly need high speed for your cleaner.
Thanks for the advice Jason. I am hoping the variable speed pump makes this a minor annoyance because I spent all last year trying to find the leak, replacing pipes, buying new valves, digging up pipes, taking appart and re-putting my filter back together, going to the pool store and anking questions, etc. I tried everything I was told at the store and everything people on this message board advised. The air leak got better as I fixed things, but it never went away completely.
I see that you have a 1/2 HP Wisperflo for a 20K pool. I am wondering if that would work on my pool as a replacement for the Hayward 1HP superpump I have right now.
I see that you have a 1/2 HP Wisperflo for a 20K pool. I am wondering if that would work on my pool as a replacement for the Hayward 1HP superpump I have right now.
Yes, the 1/2 HP WhisperFlo would probably work just fine. Getting a two speed pump instead would save you more on electricity.
- May 3, 2007
- 16,875
- Pool Size
- 20000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
jordangregory,
Just so you understand, the 1/2 HP Whisperflo is more powerful than the 1 HP SuperPump you have now so it will likely draw in more air than you are now plus it will use more energy than you do now. The 1 HP SuperPump is one of the smallest in ground pumps on the market although you wouldn't know it by the label.
Just so you understand, the 1/2 HP Whisperflo is more powerful than the 1 HP SuperPump you have now so it will likely draw in more air than you are now plus it will use more energy than you do now. The 1 HP SuperPump is one of the smallest in ground pumps on the market although you wouldn't know it by the label.
If I get a two speed wisperflo and run it on low, will that draw less water than my superpump?
- May 3, 2007
- 16,875
- Pool Size
- 20000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
Yes, but they do not make a 1/2 HP Whisperflo two speed. The smallest is the 3/4 HP Whisperflo WFDS-3 or WFDS-24 (uprated) but this is a significantly more powerful pump so you will never be able to run it on high speed for vacuuming or running your cleaner.
The SuperPump comes in a two speed version so you could just replace the motor instead of the entire pump which would save you both money and time in installation and plumbing.
But I would encourage you to find the problem instead of trying to work around it. In the long run, it will make the pool much easier to maintain.
I still think it is related to how you have the valve set between the skimmer and wall port. If you leave both open while the cleaner is running, you might have better luck. When you restrict the flow by using only the skimmer with the cleaner, there is so much head loss that the pump is starved of water so you need to have another source of water. Running both ports open should help but you may need to adjust the flow between the two to get the cleaner to work properly and to prevent air from swamping the pump.
The SuperPump comes in a two speed version so you could just replace the motor instead of the entire pump which would save you both money and time in installation and plumbing.
But I would encourage you to find the problem instead of trying to work around it. In the long run, it will make the pool much easier to maintain.
I still think it is related to how you have the valve set between the skimmer and wall port. If you leave both open while the cleaner is running, you might have better luck. When you restrict the flow by using only the skimmer with the cleaner, there is so much head loss that the pump is starved of water so you need to have another source of water. Running both ports open should help but you may need to adjust the flow between the two to get the cleaner to work properly and to prevent air from swamping the pump.
Thanks for the tip. I am not sure I can figure out how to replace s motor on my own, but I could buy a new pump. Would a 3/4 hp two speed superpump do the job?
And I agree it would be best to find the problem, but I have done everything I can think of. I cant find an air leak anywhere
And I agree it would be best to find the problem, but I have done everything I can think of. I cant find an air leak anywhere
- May 3, 2007
- 16,875
- Pool Size
- 20000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
I still think you are missing my point here. If the suction is TOO high, then even the best seals will leak. So to eliminate the air leak, you may just need to reduce the suction. Please try this experiment:mas985 said:
First, with no cleaner attached to the skimmer:
1 -Set valve to skiimer open 100% and wall port open 100%, record the filter pressure.
2 -Set valve to skiimer open 100% and close wall port, record the filter pressure.
3 -Set valve to close skiimer and wall port 100% open, record the filter pressure.
Attached the cleaner and repeat 1 & 2. report back the filter pressures.
Also, the smallest two speed SuperPump is the uprated 1 HP (SP2607X102S) which has the same head curve as the pump you have now only in the two speed version.
Ok. I think I have got it now.
I am opening my pool this week, so I will post the pressures here soon.
I do know that with both ports open, i do ok, even with the cleaner mh problem arises when when the filter gets dirty and the pressure goes up to about 20 psi
I would often go to work with the pump doing ok, when i got home, the pump would be half filled eith air and suction was lost at both ports
I know for sure if i have either port shut and the cleaner attached, i lose all suction immediately. Assuming it is a problem with too much suction, what is the solution?
I am opening my pool this week, so I will post the pressures here soon.
I do know that with both ports open, i do ok, even with the cleaner mh problem arises when when the filter gets dirty and the pressure goes up to about 20 psi
I would often go to work with the pump doing ok, when i got home, the pump would be half filled eith air and suction was lost at both ports
I know for sure if i have either port shut and the cleaner attached, i lose all suction immediately. Assuming it is a problem with too much suction, what is the solution?
- May 3, 2007
- 16,875
- Pool Size
- 20000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
If you don't get air with both ports open, then leave both ports open.
However, I still don't quite understand why a dirty filter allows more air into the system. My only thought is that as the filter gets dirty, flow rates are reduced, the suction in the pump is reduced and the pump lid seal is not as good allowing for air to enter the pump lid. You need to make sure there is plenty of pool lube on the lid gasket and the lid is on very tight.
However, I still don't quite understand why a dirty filter allows more air into the system. My only thought is that as the filter gets dirty, flow rates are reduced, the suction in the pump is reduced and the pump lid seal is not as good allowing for air to enter the pump lid. You need to make sure there is plenty of pool lube on the lid gasket and the lid is on very tight.
I have plenty of lube, a new gasket, and the lid is on super tight.
I think it has to be coming from somewhere else
I think it has to be coming from somewhere else
I was looking back through the posts and noticed mention of a bypass valve in line with the cleaner. What exactly is a bypass valve and what does it do?
Various things are sometimes bypassed, usually heaters, occasionally filters. A bypass allows water to flow round the heater/filter either instead of or in addition to the water that goes through. This not common but when it is done it might be done for a couple of different reasons. With a heater it is normally done to eliminate the flow resistance from water passing through the heater to improve the overall efficiecy of the system. With a filter it might be done to allow a higher total flow rate than the filter is designed to handle, for example when you have a very large pump powering both the pool and the spa jets. The filter only need to be large enough for the pool.
Mark,
I am still trying to wrap my head around the whole "head" thing.
You stated that I had "about 70 GPM @ 47' with a filter pressure of about 11 PSI. But keep in mind that when you change pumps, unless the head curves are identical, the head loss and flow rates change as well."
I was planning to change to a 3/4 HP pump. What would that do to my head and GPM?
I am still trying to wrap my head around the whole "head" thing.
You stated that I had "about 70 GPM @ 47' with a filter pressure of about 11 PSI. But keep in mind that when you change pumps, unless the head curves are identical, the head loss and flow rates change as well."
I was planning to change to a 3/4 HP pump. What would that do to my head and GPM?
Is there a way to find out exactly what my "head" is. I saw something mentioned about vacuum gauges.
- May 3, 2007
- 16,875
- Pool Size
- 20000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
Think of the plumbing and your pump as two separate machines. The head loss in your plumbing is dependent on flow rate. However, the flow rate of the pump is dependent on head loss. So you have two curves. The head curve of the pump and the head curve of your plumbing. Where they cross is the operating point of the pump and plumbing. Change the pump and/or plumbing and the operating point changes.
But really you needn't place all that much importance on knowledge of the exact operating point. It really doesn't matter much. But if you must know, the best method of measurement, besides a flow meter, would be to use a pressure gauge and a vacuum gauge. To get total head loss of the entire plumbing, you must measure the pump pressure at the pressure side drain plug of the pump and the pump vacuum at the suction side drain plug. Once you have both measurements you calculate head as:
Return head = Return Pressure (PSI) * 2.31
Suction Head = Suction (in hg) * 1.13
Total Head = Return Head + Suction Head
Then from the pumps head curve, you can look up the GPM. However, this is only good for that pump.
If you want to know the flow rate for other pumps, then you need to determine your plumbing curve. The plumbing curve is the curve which defines how the plumbing head loss changes with flow rate. You can determine the plumbing head curve from your old pump. The curve will have the relationship of:
Head loss (ft) = C * GPM^2
where C is a constant for your plumbing. Since you have GPM and head loss from your old pump, C can be calculated. The equation can then be used to plot over any pump head curve to find the operating point.
However, I have a couple of spreadsheets that allow you to do this with little work. They are under "Pump Modeling Tools" in my sig. "GPM Estimate" will estimate the GPM for a number of pumps using one of several different methods. Once the plumbing curve is "Calibrated", you can then change the pump model in other columns to see what the new flow rate will be. If you have a vacuum gauge, use "Head2GPM" tab. If not, use the "PSI2GPM" tab.
Another spreadsheet is "Pump Cost" which will compare not only the flow rates between pumps but also the lifetime cost of pumps. This is useful if you are trying to decide if a pump is worth the cost and is normally used to determine if a variable or two speed pump is more economical over the life of the pump. For low energy rates, a two speed tends to win out.
But the real question is: What are you trying to accomplish?
But really you needn't place all that much importance on knowledge of the exact operating point. It really doesn't matter much. But if you must know, the best method of measurement, besides a flow meter, would be to use a pressure gauge and a vacuum gauge. To get total head loss of the entire plumbing, you must measure the pump pressure at the pressure side drain plug of the pump and the pump vacuum at the suction side drain plug. Once you have both measurements you calculate head as:
Return head = Return Pressure (PSI) * 2.31
Suction Head = Suction (in hg) * 1.13
Total Head = Return Head + Suction Head
Then from the pumps head curve, you can look up the GPM. However, this is only good for that pump.
If you want to know the flow rate for other pumps, then you need to determine your plumbing curve. The plumbing curve is the curve which defines how the plumbing head loss changes with flow rate. You can determine the plumbing head curve from your old pump. The curve will have the relationship of:
Head loss (ft) = C * GPM^2
where C is a constant for your plumbing. Since you have GPM and head loss from your old pump, C can be calculated. The equation can then be used to plot over any pump head curve to find the operating point.
However, I have a couple of spreadsheets that allow you to do this with little work. They are under "Pump Modeling Tools" in my sig. "GPM Estimate" will estimate the GPM for a number of pumps using one of several different methods. Once the plumbing curve is "Calibrated", you can then change the pump model in other columns to see what the new flow rate will be. If you have a vacuum gauge, use "Head2GPM" tab. If not, use the "PSI2GPM" tab.
Another spreadsheet is "Pump Cost" which will compare not only the flow rates between pumps but also the lifetime cost of pumps. This is useful if you are trying to decide if a pump is worth the cost and is normally used to determine if a variable or two speed pump is more economical over the life of the pump. For low energy rates, a two speed tends to win out.
But the real question is: What are you trying to accomplish?
An accurate vacuum gauge and pressure gauge will get you pretty close. I have a -30"HG to 30psig one that's glycerin filled and I have -4.5" suction and 11psig discharge pressure so my total head is just over 30'.
Should I assume that the pressure side drain plug as the place where water is pushed back into the pool and the seuction side drain plug as where the water is pulled back into the filter - IE the two pull water returns?
And where would I get a vaccum gauge, pressure gauge and a flow meter?
And where would I get a vaccum gauge, pressure gauge and a flow meter?
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