Last evening I noticed that the pressure gauge on my filter hasn't moved at all over the past month. Normal operating pressure lately has been 12 psi. I haven't had a huge problem with dirt lately, but I would have expected to see some movement. I replaced this gauge this spring, and was wondering if it had gone bad again. I started closing the outlet valve from the filter (valve in the line, not the multi.) As I closed the valve, the pressure slowly rose, but the sound of the pump didn't change at all. I finally closed the valve entirely, and the total pressure difference was only 6 psi (from 12 to 18) I know the valve was restricting most if not all of the water, because the water in the pump pot stopped moving. Still, the sound of the pump did not change. I didn't want to leave the valve closed and the pump running long enough to check the waterflow at the return, but it should have been very minimal or completely stopped at that point.
The normal pressure at the return seems lower than it was last year. This is subjective, since I don't recall what my operating pressure was last year, it just feels lower.
It doesn't appear to be a bad spider gasket, since I didn't get any flow through the backwash line, which would have been the only way out with the valve closed.
Shouldn't the pressure on a DYNII-N1-1 1HP get higher than 18 psi? Sorry, but I have no clue what my head is. The plumbing is 1-1/2". The total run from filter to return is about 14' with 9 elbows, total run from the pump to the filter is 3' with two 45s and one 90, and the total run from the skimmer to the pump is about 8' with 5 elbows, if that helps any.