Dead vacuum or DE Filter clumping?
Hayward Navigator isn't working. Pool is just over a year old and vacuum is in the pool running around full time, except when we're swimming laps because it's in the way.
I was told by my PB that the little flapper feet wear out first because of the roughness of the PebbleTec, but the pressure seemed a bit low when I stuck my hand under the vacuum.
Note: Our vacuum has never been very strong and only runs around the bottom of the pool, not up the sides at all. Our neighbors' vacuum runs entirely up the sides of their little pool to where it comes out of the water up to the coping.
The local pool store guy asked me about how often I backwash my DE filter, and I told him that I've done it regularly every 3 months, about 4 times since we started the pool. And he said that the DE will clump up in the middle like a rock and backwashing won't help, and it needed complete cleaning every 12-18 months (my pool company never told me this during pool school). Then he showed me a picture on his cell phone of the inside of a filter with big chunks in it, and said it's a pain to clean out so they charge $125 to do it. Yikes. So he said to isolate the filter and check the pressure.
When I did that, the pressure was much, much stronger, but the stupid vacuum still didn't work, so I quite possibly have two things going on here.
So my questions to the experts:
(1) Is the DE filter chunking thing for real? (i.e. do I need to open it up and clean it all out and replace all the DE?)
(2) What should I check on the Navigator that fails first? Can I rebuild the thing myself? It just can't be that complicated, right?
Thanks for the help!