Why did my filter pressure jump +6 psi?

For the last eight years the pressure gauge on my D.E. filter read 15 psi when clean and usually about 22-23 just before I backwash. FWIW, it usually takes 4 to 6 months for the pressure to go up this much.

One day last week the pressure gauge showed 16 psi, the next day it showed 22 psi - but nothing happened that I know of could have caused this jump. I tried the following to reduce the pressure:

- I backwashed the filter but when done the pressure had only dropped to 21 psi.

- Next I took the filter apart and gave it a thorough cleaning. When done, the pressure reading was still 21 psi. Before now, the pressure was ALWAYS 15 psi after this kind of cleaning.

- Next I tried a different pressure gauge, but the pressure was still read 21 psi.

- Nothing else, I'm out of ideas!

FWIW, everything seems to be operating fine, but I'd really like to understand why the sudden jump in pressure and if any problems are indicated!

Thanks, Bill

 

could simply be the pressure guage going bad.

 

[I]>>>could simply be the pressure guage going bad.

 

it is not necessarily a problem, pools run at different pressures. If filter is clean, and nothing blocking the returns, valves are open, not running through a heater, then I would not worry. If running through heater, heat echanger might be getting some build up internally if chemistry has been off or the bypass may be bad. I'm assuming DE filter? If so you can also remove grids and see what pressure is then.

 

Kind of puzzling. I agree that you might try removing the grids and see what the pressure reads with no restrictions at all. FWIW, my DE pressure reads about 9-10 when fresh. When you cleaned the grids did you just wash off the old DE or did you give them a soak in a cleaning solution before reinstalling?

 

When you cleaned the grids did you just wash off the old DE or did you give them a soak in a cleaning solution before reinstalling?

I just sprayed them off with a hose as I always do. If it's something microscopic that's adhering to the grids, I think that time and chlorine will take care of it.