Where is this pump? Are you on a well, or is this pump between your
supply and the irrigation system?

It sounds like you may have a pump between your supply and irrigation
system to increase pressure for the irrigation system. If that is the
case, the pump will block water flow when it is not activated, and if
you have tapped into the irrigation system downstream from the pump, you
will get flow only when the pump is activated. Tapping into the supply
line upstream from the pump blockage should give you whatever pressure
is there to your new line.

JD wrote:
(I've also posted this in lawn.garden, but perhaps a plumber may have an
answer to this.)

Last fall I extended my irrigation system by tapping into the main supply
line and creating a manifold with three solonoid valves and one "direct"
line with a manual valve.
I ran an additional line to the rear of my property for an "always on" hose
spigot. I didn't hook it up over the winter. Each of the irrigation valves
work well.

Now that we won't be getting any more deep freezes, I hooked up my "always
on" valve to the line running to the spigots.

To my surprise and puzzlement the pump will not supply water to this line
unless one of the irrigation valves in the manifold are open. I don't
understand this. The valves are "downstream" of the direct line and should
not have any affect on the valve that is tapped directly into the main
supply line.

It seems to me that when the manual valve is open water should flow out of
the valve to the spigot. Tests have shown that water will flow freely to
the spigot when hooked to a garden hose.

I am puzzled why the pump won't come on when the manual valve alone is open
and only when one of the irrigation valves in the same manifold is
operational.
Any thoughts would be greatly appreciated.

Jackson
Chesapeake, VA