Pentair Intelliflo3 VSF: extremely low flow rate

[scoliukos]

I have a new gunite pool that was plastered and filled last Sunday (4/21). My equipment is as follows:
Pentair Intelliflo3 VFS (1.5HP)
Pentair FNS plus DE filter (36sqft)
Pentair Mastertemp 400
5 returns + 2 skimmers

As of today, with the pump running at 100% speed, my flow rate is 13 GPM. My pool builder is not taking this seriously so I am looking for some input…
I do not have a heater bypass, but would this really affect the flow rate so drastically? Is it more likely this is a filter or pump issue? The filter is currently reading 24 PSI.

Thanks in advance!

 

[1poolman1]

I have a new gunite pool that was plastered and filled last Sunday (4/21). My equipment is as follows:
Pentair Intelliflo3 VFS (1.5HP)
Pentair FNS plus DE filter (36sqft)
Pentair Mastertemp 400
5 returns + 2 skimmers

As of today, with the pump running at 100% speed, my flow rate is 13 GPM. My pool builder is not taking this seriously so I am looking for some input…
I do not have a heater bypass, but would this really affect the flow rate so drastically? Is it more likely this is a filter or pump issue? The filter is currently reading 24 PSI.

Thanks in advance!

Unless something is in the heater blocking it, that is not the heater. Is the pump basket clogged? Skimmer basket? Open some or all of the valves after the chlorinator cell and see if the flow improves. What does the flow in the skimmer look like? You would see virtually no movement at 13gpm.

 

[ajw22]

Welcome to TFP.

I would expect at least 60-70 GPM from that setup.

Unfortunately you do not have an MPV or a heater bypass that can bypass your filter or heater to try and isolate the problem.

You could have debris from plastering blocking the pipes.

You have unions at the pump, filter, and SWG to open up sections of the plumbing.

What is your filter PSI?

 

[scoliukos]

Unless something is in the heater blocking it, that is not the heater. Is the pump basket clogged? Skimmer basket? Open some or all of the valves after the chlorinator cell and see if the flow improves. What does the flow in the skimmer look like? You would see virtually no movement at 13gpm.

Flow does not change when the other two valves are opened. We cleaned a few leaves out of the pump basket and that increased the flow by about 5 GPM. And yes, there is no movement in the skimmers.

 

[scoliukos]

Welcome to TFP.

I would expect at least 60-70 GPM from that setup.

Unfortunately you do not have an MPV or a heater bypass that can bypass your filter or heater to try and isolate the problem.

You could have debris from plastering blocking the pipes.

You have unions at the pump, filter, and SWG to open up sections of the plumbing.

What is your filter PSI?

The filter is showing 24 PSI.
I’ve asked my pool builder to come and manually clean the filter. He failed to add DE at startup, so it’s been running without that since Monday.

 

[ajw22]

The filter is showing 24 PSI.

24 PSI is too high for 13 GPM.

I’ve asked my pool builder to come and manually clean the filter. He failed to add DE at startup, so it’s been running without that since Monday.

Your builder should buy you new grids for your DE filter.

Running without DE is your problem. Your filter is clogged with plaster dust.

A DE filter should not be run without DE for more then about 10 minutes. The grids are not made to be cleaned with anything other then DE on it and cannot be effectively cleaned when clogged. Running a DE filter without DE ruins the grids.

 

[ajw22]

I recommend you put in an MPV on the filter and a heater bypass on your new pool.

Heater Bypass - Further Reading

www.troublefreepool.com

MPV Valves - Further Reading

www.troublefreepool.com

 

[1poolman1]

Flow does not change when the other two valves are opened. We cleaned a few leaves out of the pump basket and that increased the flow by about 5 GPM. And yes, there is no movement in the skimmers.

If you know how, open the filter and remove the grid assembly/cartridges, etc. Close the tank with nothing in it and try the pump. If the flow increases yo have found the problem.