SPRINKLER TALK FORUM - You Got Questions, We've Got Answers

I have replaced an existing above ground/surface system with all
in-ground heads, 8 zones, existing one inch main, 1/2 inch funny pipe to
heads. Irritrol Rain Dial-R controller, valves brand and model is unknown. I
don't see any pressure reducing devices in the system and zone valves do
not appear to be adjustable.

Plenty of pressure, dedicated City irrigation system. Nine times out of ten, when activated either by
timer, manual at the controller or at the valve, heads will pop an inch
or so and dribble. Turn off and restart them, they pop with lots of
pressure and stay on normally. This happens with Orbit spray heads in 7
zones and my RainBird impact sprinklers in another. Age of the system is
unknown, home is new to me last December and irrigation system was just
activated this week by the City. Previous owner is not available.
I re-made all wire connections at the valves, clean and tight.
Can anyone identify the two types of valves? I'm thinking of changing solenoids if I can find what these are.
I'm anxious because I just had my entire property hydro seeded, which
requires frequent watering, like every two hours for 15 minutes each
zone, 8 zones.

I don't get it, the part time operation. Yesterday they cycled and ran just fine for six start times.

I checked voltage at the controller, 26 VAC to the valves. Is it possible
the solenoids aren't opening fully at the first hit and the second try
opens them further? Just thinking outside the box...

I also checked my irrigation system pressure, steady 50 psi.

I'm currently searching this site.

Any ideas? Thanks!

Thanks for the reply. It's random and in all zones. For instance I can run my program, have 55 psi incoming, first zone opens, pressure on the main system drops to zero and the water just pukes out of the heads. Shut the controller off, run a zone manual from the controller, comes on fine, system pressure holds at 40 - 50 psi. Sometimes opening a zone at the valve works, sometimes not. I'm not losing system pressure from the city. It's a city provided, separate irrigation system, pressurized. I probably mentioned it earlier, I've shut off all heads in a zone, activated it, holds the system pressure, and no signs of any leaks coming up anywhere after half an hour in that state.

I've already had a sprinkler contractor here after the city turned on the system a couple weeks ago to repair a line my concrete contractor drove a form spike through, the system worked great when he left. The next day same old stuff happening. I'm afraid I may have to destroy my new hydro seeded lawn and run all new piping if I can't find something else wrong somewhere. I just cannot figure out why I would have great operation one minute, then the next cycle not. We just bought this home in December, so not aware of any pre-existing issues.

I have a manual gate valve in the yard coming in from the City on a one inch line, which splits and runs to three zone valve boxes, and to one line to a spigot which is full-time pressurized.

I haven't OHM'd the solenoids yet but will in the morning.