clogged return lines?

[bird]

my filter and pump were running just fine until a few nights ago. when i looked at the pool the other morning the pump was running, but no water was being circulated. i did what i normally do in such circumstances - backwashing. it always solves that problem, until now!


is it possible that my return lines are clogged? if so, how to unclog?

in the past, if i had trouble getting water to start circulating, i did either of two things:

1) put a hose with running water in the skimmer until water started to circulate, or

2) opened the pressure relief valve on the filter, and wated till water started coming out of it.

but now...nothing. the pump still works. today i even opened up the prime bucket by the punp/filter and turned it on. bubbles came into the pool, but still no water returning.

if it matters to anyone who can answer: i have a DE filter.

thanks in advance for anyone who can help out