High psi gauge when pump off, broken gauge or something else?

[slipstreams7]

The gauge on my sand filter is on 20 when the pump has been off for a few weeks. I tried tapping it with a screwdriver and the arrow seems to jiggle downward to zero but instantly comes back to 20. I think it could be a calibration issue where 20 is the new zero, but I am paranoid about pressure danger if even a remote possibility. It is a hayward Multiport variflow xl with no air relief valve that I can see.

I have opened the drain cap at the bottom of filter to let water out with no issue/explosive pressure, and the tiny drain plug under the pump. I have not been able to get the lid of the pump open and am nervous to force it until I can verify there is no hidden pressure somewhere in the system. I also haven't tried unscrewing the gauge for the same reason. Plumbing is hard pvc piping, so I haven't been able to check the pipe between pump and filter.

Based on this info, is there any chance there really is 20 psi waiting to blow off my fingers? From what I read if the pump is off then there is no pressure but I want a second opinion for peace of mind before proceeding to closing pool.

Thanks for your time and advice

 

[Bperry]

If you removed the drain plug, it isn’t possible for there to be 20psi in there.
You can unscrew the gauge slowly and if there is pressure, you will be able to hear it bleed out before it comes all the way off since they usually use tapered threads.

you can also move the multiport valve around to different positions to make sure any air that could be in there escapes.

 

[Jimrahbe]

Slip,

The paper behind the pointer often bends causing the pointer to stick..

100% bad gauge..

Jim R.

 

[HermanTX]

Also, if you have a spigot above the pump (many PB's put it on for a test) you can open that and that would verify no pressure on the system downstream of pump.

 

[slipstreams7]

Thanks for the replies everyone. I am going to slowly remove the gauge with my pliers if they will work on it. The main reason for the concern was that flicking the gauge caused the needle to move back to zero and then quickly back to 20, which led me to believe it wasn't stuck....but since the drain plug removes and all that comes out is water it's not possible like you said.

 

[borjis]

Tftestkits.com has a great reasonably priced glycerin guage replacement if you need.