High Pump Discharge Pressure 25+ PSI

[briggss3]

Operating a Century 1.5HP pump with 2 inch feed and discharge. Discharge goes through a main return, sweep manifold, and another 1 inch line that I don't know what it is for (vacuum?). Filter is a 100D Tagelus Sand Filter with multiport valve on top. All discharge lines are open, except I have no idea how the sweep manifold operates since there is no obvious block valve on it.

I am a new pool owner but generally knowledgeable about piping and valving, although I did manage to suck air into the pump draining via the skimmer (jandy valve unmarked). I went to backwash yesterday and the pressure was high when I went back online.

Pump pressure is now 25 to 27 PSI on the brand new Jacuzzi gauge. I replaced it to rule that out. Pressure is the same through the filter and through the filter bypass. When backwashing out the waste port, the pressure is about 10 PSI.

Pump 2 inch return is unblocked and I removed the diffuser plate at the pool to confirm that. Strainer baskets are clean.

I am at a loss for what to do. Is the multipurpose valve bad?

 

[briggss3]

 

[HermanTX]

Is this a new issue? What is the baseline if you are stating the 25psi is high?
What was pressure before backwash and the resulting pressure after backwash was 25psi.
Has the sand filter ever been cleaned or just backwashed?

 

[briggss3]

I think it was around 10 PSI. Not 100% sure. I just tool ownership of the house and pool. So basically it looks like the pressure went up after I did a few things.

1. Drained the pool out the waste valve about 1.5 feet down to address a very high CYA. Note I did not block anything I'm on the return lines when flushing out the waste port.
2. SUcked a little air into the pump but seems like that was no problem.
3. Refilled and backwashed and rinsed.

Before all this I think inwas 10 to 15. Going back online I am 25+.

Its a new issue and I have no idea if filter has ever been cleaned. I assumed it was a filter problem but it's also high on recirculation.

 

[briggss3]

Just pulled the multiport valve. Inside of sand filter looks good with minimal topside debris. Valve underside looks ok.

Anyone else have any idea what will cause a pump discharge to start running high whether through the sand or in bypass mode? The plumbing was working fine before I started draining and backwashing. I can't imagine it's a physical block...

 

[mas985]

I seriously doubt the pressure was ever 10 PSI with an in-floor cleaner and that size pump.

25 PSI is a reasonable filter pressure with this setup. Most in-floor cleaners require around 20 PSI at the manifold to work properly. Filter pressure is always higher than manifold pressure.

What pressure on the water valve gauge should my system operate at? - Paramount Pool & Spa Systems

Anywhere from 14 psi to 24 psi with maximum cleaning happening about 18 to 22 psi with the correct nozzle sizes installed. NOTE: Nozzle size will affect the psi on the system and how well it cleans. The system is designed and specified with certain sizes at each location. Consult the Paramount...

www.1paramount.com

 

[1poolman1]

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You have a single-speed Century motor on a Sta-Rite pump, possibly a Max-E-Glass 2 or Max-E-Pro (same pump different basket).
That pressure of 25 is not high for a pool with an IFCS. In fact, as the distribution valve changes ports, the pressure may jump even higher for an instant as one port closes before the other opens. Looks like someone did a lot of re-plumbing and installed a new distribution valve or maybe just the dome.

 

[briggss3]

You have a single-speed Century motor on a Sta-Rite pump, possibly a Max-E-Glass 2 or Max-E-Pro (same pump different basket).
That pressure of 25 is not high for a pool with an IFCS. In fact, as the distribution valve changes ports, the pressure may jump even higher for an instant as one port closes before the other opens. Looks like someone did a lot of re-plumbing and installed a new distribution valve or maybe just the dome.

Thanks very much. I won't worry about it then. For some reason I thought a normal pressure would be around 5 to 10 psi on a clean sand filter.

 

[1poolman1]

Thanks very much. I won't worry about it then. For some reason I thought a normal pressure would be around 5 to 10 psi on a clean sand filter.

The pressure you read on that gauge is the pressure in the entire system after the pump. It also depends on the size of the pump and, with a VSP, the RPM. A system with an IFCS has a lot of restriction after the filter and that is shown by the high reading even with the valve in the recirculate position, which bypasses the sand, the water just goes through the valve and back toward the pool.
Correction on identifying your pump. I just noticed the picture that has the pot in it. That's a Pac-Fab (now Pentair) Challenger. It is a 1.65 total horsepower pump, based on the motor.