New anti-siphon valve problems ....
Installed four new Orbit (I know not the best) anti-siphon valves about a month ago because my old Richdels were leaking. After installation they seemed to work fine, but since it was winter, I did not use them. What happens is this: When turned on either manually or with the controller the pressure is very low at the heads. I found that if I turn my manifold main line valve off then right back on the pressure is great and they work fine. This happens on all four stations. Turn the main line off while the siphon valve is "on" then back on again and they work fine (until they are shut off). I am baffled. Could it be the Orbit valves? I am about ready to buy one new valve - different brand - and see if that cures it. Any ideas?
Thanks,
Jerry