Hey everyone,

Sorry if this topic has been discussed ad nausea here but I am at a
loss. I have a 10 Zone sprinkler system in that I am trying to blow
out myself to save some money. I have a setup that looks similar to
this:

http://www.sacreativeservices.com/forum_stuff/febco.jpg

but without "C." I swore last year when I paid to have the system
blown out, they hooked their compressor up to A. When I do this, all
the air just comes out the top of the backflow preventer. I have the
bottom blue valve closed along with the main shutoff line. I have the
top left blue valve open. I also have all the sprinkler valves closed
in hopes to build up about 40PSI in the supply line and then stand at
the controller and cycle each valve. I am unable to get any pressure
when hooking the compressor to A or B. What am I doing wrong?

TIA,

Derek