filter pressure change

[jvmagic]

Hi,

1) I have a leak in my solar plumbing fixed about a week ago.
2) removed a lot of leaves from skimmer basket and basket in filter plumbing (don't know the tech name).

I thought that my filter pressure has always been around 20 but I currently noticed that when the solar is not on the pressure is down to 12 or so and the motorpump makes a louder noise compared when the solar is on and the pressure is around 20-21.

can someone please give me some insight? Is this normal?
the pool water is nice n clear but I just want to know why the pressure changes..didn't notice this before.

thanks

 

[JohnT]

Check the impeller, which is where the water goes when it leaves the strainer basket. A little goo in there can cause a loss of flow.

 

[Bama Rambler]

Where is your solar panels located? Ground level, on the roof, how high in feet?
How much additional piping is added by the solar system?
What size and type & brand are your panels?

With a lower pressure in the system you're physically pumping more water so that alone could account for the increased noise. Also if you have a suction restriction you could be cavitating the pump. You'd probably notice air bubbles in the pump strainer if that was the case.

 

[jvmagic]

Where is your solar panels located?
on the roof of my two story home (second story)

How much additional piping is added by the solar system?
I assume a couple of hundred feet.

What size and type & brand are your panels?
I have eight panels...don't know the size...they were there when I moved in.

With a lower pressure in the system you're physically pumping more water so that alone could account for the increased noise. Also if you have a suction restriction you could be cavitating the pump. You'd probably notice air bubbles in the pump strainer if that was the case.
I'm almost positive that the pressure was 20 + no matter if the solar was on or not. Now like I mentioned, it fluctuates from 12 - 20 (solar off-on).
The impeller is not plugged up (I put my fingers in as much as I could; no blockage).
No bubbles in the pump strainer either.

thanks again

 

[Bama Rambler]

Since your panels are on the second story and it adds a couple hundred feet to the plumbing I'm not surprised that it add's 20 feet of head. Which it should. I think what you're seeing now is more "normal" than what you were seeing before. Maybe you had a partial blockage in the discharge piping causing the pump run at higher pressure all the time.

 

[jvmagic]

understood and thank you.......why the fluctuation of pump noise though???

 

[Bama Rambler]

That has to do with water moving through the pump cavity and the load on the motor. I know it seems weird but the higher the discharge pressure less water is moved through the system and less load on the motor. So, at lower pressure the water is moving faster through the pump cavity (i.e. more noise) and the load on the motor is increased (i.e. more noise).