have 40 gal power vent, 2007, have had to disconnect line @ top of unit to remove sediment x 5 because of low pressure, this time 0 results, only a dribble, even tried reverse h2o hammer, what?

I'm having a problem understanding your problem.

have had to disconnect line @ top of unit What line? Hot or cold? What is "sediment x 5"?
even tried reverse h2o hammer, Please explain.
Is it your complaint that you have zero pressure on
1- The entire house?
2- All the hot water faucets?
3- Some of the hot water faucets?
Please post back with more details. Tom