Pentair Intelliflo VSF pump Pressure limit warning - day 1 of new pool

blgreen

Member
Aug 22, 2020
5
Saint Louis, MO
HI - I'm in the final stages of my new pool build. My PB increased pump to a 3HP Pentair VSF to ensure the system had enough water pressure/GPM for 2 Pentair Magic Bowls water features and 1 3ft wide rain waterfall feature. Pool is 14 x 29; 11k gallons. A nice selling feature of the VSF pump is its variable speed drive plus the ability to set the pump to a specific flow. So far the pump only operates WITHOUT a pressure limit warning when set to run at RPM's. When setting the pump to a specific flow the pump starts up ok and after several minutes it shows "Pressure Limit" error on LCD screen and the GPM readout drops significantly. Backwashed multi times with no improvement. Pump strainer basket looks ok; clear water no bubbles to indicate air, etc. I have 2 skimmers (2" line) and 3 returns (1.5" line), plus 1.5" line for the magic bowls, and separate 2" line for Waterfall. Total of 5 valves.
I knew I had problems with my PB when he suggested we may have to increase the pump size because of the water features. (We already have a smaller pool running a very nice 3HP VSF pump). PB tells me he is having lunch with his Pentair rep and will run the problem by him. He calls me on Monday and said he spoke with the Pentair rep and has an easy solution. His solution is to put a Tee pvc piple connection after the pump and before the sand filter; run left tee connection to filter and the right back in the main return line bypassing the filter. In my opinion essentially creating an always on RECIRCULATING mode for ~ 50% of my pool water. This solution seems VERY sketchy. I feel it would lead to poor water quality and basically working around a problem instead of solving it. (IMO he just wants to do a quick fix to move on; I fear he may have installed the filter wrong/damaged, etc). Is the filter too large? Am i trying to push too much GPM? Each water feature requires ~ 20GPM (3 water features total). Please see 7 tests cycles below trying both manually setting pump for RPM and setting for a specific GPM.

7 Tests with data:
In 6 of these tests I decided to close the valves on both water features to eliminate that from being a potential issue. All other valves were open.
Test 1: 6:20PM, 82GPM (prog #4). @ 6:30PM pump fell to 67GPM and pressure limit error.
Test 2: 6:30PM, 63GPM (prog #3).
@ 6:35PM held at 63GPM
@ 7:15PM held at 63 GPM
@ 7:23PM fell to 51GPM and pressure limit error.
Test 3: 7:25PM, 82GPM (Prog #4).
@ 7:50PM fell to 21GPM and pressure limit error.
Test 4: 8:10PM, 1700RPM (Prog #1)
@ 8:15 1700RPM, run at 23GPM
@ 8:31 1700RPM, run at 26GPM
Stopped test, no errors on screen.
Test 5: 8:31PM, 2250RPM (Prog #2)
@ 8:45 2250RPM, run at 45GPM
@ 8:50 2250RPM,run/fell to 42GPM
Stopped test, no errors on screen.
Test 6: 8:55PM, opened both water feature valves and manually set pump to 2500RPM.
Stopped test, no errors. 42GPM
Test 7: 9:45AM, 63GPM (Prog #3).
@ 9:50AM fell to 59GPM and pressure limit error. (Water feature valves were turned off for this test).

Alarm Logs show B70030

I would appreciate any technical feedback and/or advice on how to respond to my pool builder on his "TEE connector" before the sand filter. (My gut tells me to push back and watch everything he does)

Thanks!
Brad
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
19,495
Bedford, TX
Brad,

If he is "by-passing" the filter then he must think the filter is too small causing too much back pressure.. I have no idea if that is correct or not..

Let's get someone that knows, involved... Calling @JamesW

I really don't understand the fuss if the pump runs all your water features in the RPM mode.. Just set the RPM until your water features work.. The GPM feature is more hype than a requirement.

Thanks,

Jim R.
 

JamesW

TFP Expert
Mar 2, 2011
21,146
What is the system pressure (from the pump display), filter pressure, rpm and gpm on programs 3 and 4?

Check the flow, gpm, rpm, system pressure (from pump keypad) and filter pressure at 3,110 rpm and 2,350 rpm.

Do you have a picture of the system?

What is the pump pressure limit set to in the pump settings?

Do you have automation?


 

JamesW

TFP Expert
Mar 2, 2011
21,146
Do both skimmer lines tie together underground and then there is only a single 2" line going to the suction of the pump?

Is there a main drain?

Do you close the return lines when you want to use the water features?
 

blgreen

Member
Aug 22, 2020
5
Saint Louis, MO
Do both skimmer lines tie together underground and then there is only a single 2" line going to the suction of the pump?

Is there a main drain?

Do you close the return lines when you want to use the water features?
Hi - both skimmers lines tie together to a single 2" line. No main drain. Keep return lines open when using water features.
Thanks
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
19,495
Bedford, TX
both skimmers lines tie together to a single 2" line.
bl,

Just to be clear.. I assume both 2" lines come to the equipment pad into a valve or valves and then go into your pump.

Is that true, or is there only one 2" line coming out of the ground and into your pump???

Thanks,

Jim R.
 

JamesW

TFP Expert
Mar 2, 2011
21,146
Keep return lines open when using water features.
You should close the returns when using the water features. It takes too much flow to try to run the features while the returns are open. The features are the returns while they are on.

You should have automation to make all of this work easily with automated valves. If you don't have automation, the builder should have recommended it.

If you only have a single 2” suction line, you should keep the flow to a maximum of 63 gpm so that the water velocity in the suction line does not exceed 6 feet per second.

What is the system pressure (from the pump display), filter pressure, watts, rpm and gpm on programs 3 and 4?

Check the flow, watts, gpm, rpm, system pressure (from pump keypad) and filter pressure at 3,110 rpm and 2,350 rpm.

Do you have a picture of the system?

What is the pump pressure limit set to in the pump settings?
 

blgreen

Member
Aug 22, 2020
5
Saint Louis, MO
What is the system pressure (from the pump display), filter pressure, rpm and gpm on programs 3 and 4?

Check the flow, gpm, rpm, system pressure (from pump keypad) and filter pressure at 3,110 rpm and 2,350 rpm.

Do you have a picture of the system?

What is the pump pressure limit set to in the pump settings?

Do you have automation?


System Pressure varies depending on program - when set to flow it fails and usually falls into the 20's GPM. When program set to RPM it will hold in the 40's GPM.
Filter pressure varies from 30 - 40 PSI
RPM on prgram 3 is not set (program 3 is set to 63 GPM, but errors out and GPM falls into 20's. program 4 is set to 83GPM with same results). I have to set the program to either flow or rpm; when set to flow the LCD gives me no RPM values....just GPM.

3110 RPM Test Results = 22 PSI on Filter gauge
2350 RPM Test Results = 15 PSI on Filter gauge
(When set to RPM the pump LCD only shows RPM and watts)
63 GPM Test Results = 22 PSI on Filter gauge
83 GPM Test Results = 23 PSI on Filter gauge
(When set to GPM LCD shows pressure limit error immediately following priming)

Pumps Limits = 450/3450 GPM

No automation

The PB installed the largest Pentair residential sand filter; the specs show it can handle 100GPM. My pool is not very large (11k gal); PB upsized pump after I asked him if a booster pump was needed for water features. He then told me he had to up the sand filter size. So he went large; could the large sand filter be causing an issue? Great to have a big filter.....but I may not have enough suction/skimmers to supply enough water back to pump???

I appreciate your help!

Thanks,
Brad
 

Attachments

JamesW

TFP Expert
Mar 2, 2011
21,146
What is the maximum pressure set to?

To Set Maximum System Pressure:
1. Check that the green power LED is on.
2. Press Menu.
3. Press Select to select “Settings”.
4. Use the Up or Down arrows to scroll to “Min/Max”. Press Select.
5. Use the Up or Down arrows to scroll to “Set Maximum Pressure”.
6. Press Select to change the setting. The cursor will appear in the first number column (ones).
7. Press the Up or Down arrows to edit the maximum flow rate setting from 1 to 50 PSI.
8. Press Save to save. To cancel, press Back to exit edit mode without saving.
9. Press Back to exit.
 
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JamesW

TFP Expert
Mar 2, 2011
21,146
could the large sand filter be causing an issue? Great to have a big filter.....but I may not have enough suction/skimmers to supply enough water back to pump???
The filter is not too big. Bigger is better. I would have used a TR-140, but the TR-100 is fine.

You only need 60 gpm for the features. Just turn off the returns and run only the features.

The below video shows how to get system psi from the keypad by pressing the right arrow.

See how the system pressure from the keypad differs from the filter pressure.

 

JamesW

TFP Expert
Mar 2, 2011
21,146
You should not be using Filter Bypass because debris will get in the salt cell plates/blades and in the heater, which can clog either one. I would remove the cell and check for debris. Also, remove the thermal regulator to check for debris.

 

blgreen

Member
Aug 22, 2020
5
Saint Louis, MO
Thank you for all the information. I went back through the settings menu following the steps above. This time when I scrolled through the settings menu using the down arrow button I went past the "Key Error!" message by hitting down arrow again and then was at the PSI setting. I then changed from 30 to 50PSI. (I'm calling myself out on the user error when scrolling through settings in case someone else sees the "Key Error" and assumes they are at the end of the settings list).
Result after increasing Max PSI to 50 is the pump ran for 2 hours at 63GPM for Test #1; now performing Test #2 running at 83GPM. So far it's holding at 83GPM for about 3 hours. Sand Filter PSI ~ 24. I'll continue to watch the GPM and report results.
Thanks!
Brad
 

JamesW

TFP Expert
Mar 2, 2011
21,146
You should be able to see what pressure the pump is reading from the keypad.

I recommend shutting the return line when using water features so that you can use less flow and get the same effect.

You don't need returns when the features are on.