Pressure Gauge

cledee

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Jun 23, 2020
403
North East
Pool Size
18000
Surface
Vinyl
Chlorine
Liquid Chlorine
I replaced my pressure gauge this year with a Glycerin one from TF. For some reason my gauge goes down instead of up as it gets dirty. It happened with my previous gauge as well. Has anyone else experienced this?

I thought maybe there's build up somewhere, but I just put in fresh cartridges and the pressure is back to normal from when I opened the pool and the return jets are strong.
 
I don't think you're getting any responses because it just doesn't make sense. Maybe you can elaborate on the problem or phrase it in a different way? Your gauge is reading 6 lb now. You're saying as filter picks up more debris and gets dirty, the pressure drops?
 
I don't think you're getting any responses because it just doesn't make sense. Maybe you can elaborate on the problem or phrase it in a different way? Your gauge is reading 6 lb now. You're saying as filter picks up more debris and gets dirty, the pressure drops?
Correct. When I opened the pool it was reading 6lbs. After a week it dropped to about 4 1/2-5lbs and I decided to open up the filters after ruling out everything else. I figured the pressure would go up, not down as the filters got dirty.
 
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Have you checked for a suction side leak & looked for a clog (checked impeller)?
 
Have you checked for a suction side leak & looked for a clog (checked impeller)?
Yes, I made sure there were no leaks. The return jets are very strong. I've had a clog before and usually I would get low pressure on the gauge, but I would also get bubbles and weak flow on the return jets and the water starts to get dirty. No clog in the impeller. It will probably take awhile for me to have to change filters since the pool was a swamp when I opened, so my guess is, I won't have to switch until late August or early September and that's probably when I will get the low pressure reading again.
 
is there a relief/bypass valve on the filter to limit the pressure when the filter is dirty?

Is it possible the filter is losing it's seal or how it's seated in the housing and water bypass after it dirty?
 

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What exact pump do you have? Update your signature with correct filter and pump.
A Hayward 4025 (C4025) is a cartridge filter.

Is your pump variable speed (VS)?
If so, at what rpm are you running?
Be sure to check filter pressure at the exact same rpm.
 
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What exact pump do you have? Update your signature with correct filter and pump.
A Hayward 4025 (C4025) is a cartridge filter.

Is your pump variable speed (VS)?
If so, at what rpm are you running?
Be sure to check filter pressure at the exact same rpm.
I just realized I had a picture from last year. Here's my pump and filter and plumbing. There's a heater connected behind the shed. The pump is not a VS.
 

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I posted a picture of my equipment and plumbing.
Great - correct you signature to reflect your pump (manufacturer, model and horse power) and your filter details.

With a single speed pump (or a VS at a given speed) the filter pressure should rise as the filter gets dirtier.
Have you changed the handle position of any valves?
Do you have an external heater bypass?
Any chance the internal heater bypass is fluctuating, allowing the water pressure to change?
 
Great - correct you signature to reflect your pump (manufacturer, model and horse power) and your filter details.

With a single speed pump (or a VS at a given speed) the filter pressure should rise as the filter gets dirtier.
Have you changed the handle position of any valves?
Do you have an external heater bypass?
Any chance the internal heater bypass is fluctuating, allowing the water pressure to change?
There's only 2 options on the pump, Filter or backwash (I don't typically dump water unless the water is too high). There's no external heater bypass.
 
There's only 2 options on the pump, Filter or backwash (I don't typically dump water unless the water is too high). There's no external heater bypass.

To clarify - your pump doesn't have a filter or a backwash option. And since you have a cartridge filter, it doesn't have a filter or a backwash option either. You do have a 3-way Jandy valve between the pump and filter - this valve allows water to go from the pump to the filter or from the pump to what appears to be a drain/waste line. This drain/waste line would allow you to lower the pool water level a bit. It does not backwash the filter.

Don't forget to update your signature. See post #14.

Try running the filter without the cartridges installed and see if the pressure drops.

If you turn the pump on and it has "normal" pressure which eventually drops to a lower pressure, what happens if you shut the pump off for say 30 minutes or so and then start the pump up again?
Does this "normal" pressure and then lower pressure repeat itself? If so, is it in about the same amount of time?

Is the pump basket area full of water or is there air that accumulates over time amd that is when the pressure drops?

When the pressure drops, have you tried purging the filter of air to see if the pressure gauge reads different?

Is the water level 1/2 way up the height of the skimmer throat? Is there a whirlpool in the skimmer or is the water just flowing over the skimmer weir door gently?
 
To clarify - your pump doesn't have a filter or a backwash option. And since you have a cartridge filter, it doesn't have a filter or a backwash option either. You do have a 3-way Jandy valve between the pump and filter - this valve allows water to go from the pump to the filter or from the pump to what appears to be a drain/waste line. This drain/waste line would allow you to lower the pool water level a bit. It does not backwash the filter.

Don't forget to update your signature. See post #14.

Try running the filter without the cartridges installed and see if the pressure drops.

If you turn the pump on and it has "normal" pressure which eventually drops to a lower pressure, what happens if you shut the pump off for say 30 minutes or so and then start the pump up again?
Does this "normal" pressure and then lower pressure repeat itself? If so, is it in about the same amount of time?

Is the pump basket area full of water or is there air that accumulates over time amd that is when the pressure drops?

When the pressure drops, have you tried purging the filter of air to see if the pressure gauge reads different?

Is the water level 1/2 way up the height of the skimmer throat? Is there a whirlpool in the skimmer or is the water just flowing over the skimmer weir door gently?
I actually updated my signature yesterday. It's a Hayward Pump, just haven't had an opportunity to add the model # and the Horse Power since I didn't go into the shed yesterday.
I haven't tried without the cartridges. I will try that this weekend.
I've tried turning the pump off for 30 minutes and then turning it on and the normal pressure repeats itself, in similar amount of time.
The Pump basket is full of water. I do not notice any air or bubbles that build up over time. That only thing that would cause that is a skimmer that is full, pump basket that is full or a blockage on one of your lines. I check these constantly since we get a lot of leaves.
The water level is actually higher than 1/2 way up. Because the water level is higher it's flowing gently.
 
Everything looks ok in the plumbing routing. I assume that the loop that's running outside the building and back is feeding the heater.

Unless there's something wrong in the filter body, i don't see anything that would cause the gauge to show lower pressure as the filter gets loaded with debris.
 
The only way I was able to replicate this issue was by having skimmer sock in for more than a couple of days and it showed lower pressure, but when I was having issues before it was without a skimmer sock on. Maybe there was a partial clog somewhere in the system, I don't know. I do get a lot of egg corns and though my pool cleaner does a great job of getting most, some do get through the drains sometimes. I even have a surface cleaner now due to my neighbors forest .
 
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