Can't get past no flow on Pentair SWG - Any ideas on what else to check?

mchartra

Bronze Supporter
Oct 8, 2013
3
Canton MI
Hey gang. We have had our pool since Spring 2015. I have posted in the past about concern that I seem to have to run the pump pretty high for the flow detector to engage allowing the SWG to run. I have a Pentair Intelliflo VSP and IC40.

I've found that I need about 1,800 RPM to keep the flow high enough for the SWG to operate.

I am frustrated with pool opening this season as I keep getting a Low flow error even with the pump running as high as 2,500 RPM.
-The strainer and skimmer baskets are clean
-I can't see any leaks in the plumbing.
-Water in the pump strainer basket looks fine -it's full with not too many air bubbles at the top
-Water sounds normal running through the filter/gas heater.
-Have a Sand Dollar filter which was back washed yesterday.
-Today, I cleaned the SWG with recommended acid/water mix. There was some buildup on the fins when I opened it but I think it was more some organic gunk that made its way through the sand filter as a quick spray of the fins with the garden hose and they were clean before acid washing. The acid didn't bubble much either and I'd cleaned the SWG last season so it doesn't surprise me. I doubt there was much calcium buildup.

Short of a faulty switch, are there any other things I could test/check to figure out my flow problem? Any way to test flow or the switch with a multimeter?

Since the switch does activate if I power cycle and turn it all back on and run at a high RPM so I know it's not completely faulty but I question whether I do have low flow or a "tired" switch that won't stay engaged.

PS: I've always questioned the way the plumbing was run. Take a look at the pics of my setup. I have quite a few 90 deg elbows from the sand filter to the water heater and then to the SWG.

Part of the problem is the gas fitter had to flip the heater 180 deg out of concern that the heater exhaust was too close to our dryer vent.

I am sure this is a contributing factor to lower velocity water by the time it hits the SWG unless someone can tell me otherwise. Could any cleanup of the plumbing like bracing and angling with a slight slope towards the heater and then SWG help with flow?

Any advice from the veteran experts would be much appreciated.. Thank you!
 

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Flying Tivo

Well-known member
Jan 24, 2017
1,627
Monterrey, NL, Mexico
The first thing i would check is putting the filter in recirculate mode and check flow/pressure again. You dont have a heater manual bypass that i can see in the pictures. It wouldn't be that hard to instal one. That is so we can rule out the heater as a restriction. Did you try to disassemble the flow switch? You could have some debris in there. Last thing would be faulty switch.
 

mchartra

Bronze Supporter
Oct 8, 2013
3
Canton MI
The first thing i would check is putting the filter in recirculate mode and check flow/pressure again. You dont have a heater manual bypass that i can see in the pictures. It wouldn't be that hard to instal one. That is so we can rule out the heater as a restriction. Did you try to disassemble the flow switch? You could have some debris in there. Last thing would be faulty switch.
Thanks! I am now thinking I do have a flow issue as the return line jet didn't seem to have a strong flow coming out of it when I checked last night w the pump at 2500 RPM. If I recall, at that speed, it should feel relatively strong. Great suggestion on recirc mode. Was thinking about it this AM. I bought a bladder drain hose attachment and ran it for a while inserted into the skimmer inlet and manually turning my skimmer/bottom drain valve on/off w the pump disconnected. Also ran my shop vac w pump attachment and drained the skimmer line at the skimmer. I figured there might have been debris lodged in the skimmer return line as it didn't appear to have much suction but the water kept coming out clear.. Puzzling. Even switching to 100% floor drain or skimmer, doesn't seem to vary the flow and highly unlikely both lines are plugged unless it's at the valve near the pump. I might have to open it up and take a look but it appears to fill the strainer basket as expected on start-up...
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
17,888
Bedford, TX
Mc,

1800 RPM sounds about right with a heater.. That is just a pretty common RPM from what I see here at TFP..

I suspect that your filter is the issue. I know you backwashed, but if the return flow at the eyeballs is low, then what else could it be?

Does the filter pressure look normal after backwash?

What non-TFP chemicals have you used lately?

I guess it could be something in the MVP, but I doubt it.

It might be time to do deep clean of the filter.

Thanks,

Jim R.