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

I have an old HydroRain 9 zone controller. Three valves that share a common box do not turn on electronically. The valves do work correctly, however, when I turn on valve (via the control box) AND turn the bleeder screw on the individual valves.

I changed the diaphragm and spring in one of the valves last night, but this did not fix (or change) the valve's behavior.

My hypothesis is that the solenoids of the 3 valves are not properly grounded (they share a common ground wire).

Is this a reasonable conclusion?

Thank you!

Since my first email, I have collected some more data. I
used a volt meter to measure the current flow through the hot wire to the valve box: 24 volts at the control box and 24 volts at the valve box, a good thing. This means, I believe, that the ground wire is working fine, since I used the ground wire to complete the circuit with the volt meter.

I was able to make all 3 valves function propertly by turning the bleed screw on all the way. So I know that the valves are mechanically sound.

When I turn on any of the 3 valves, I hear the solenoids trying to work. But since all 3 are not turning on, I now believe that all 3 solenoids are defective. So I am going to replace all 3 valves.

I now have (old) Hydrorain valves. Do you know if I can buy replacements valves that are compatible? Then I can just replace the solenoids and top part of the valves, leaving the bottom part of the valves in place. This would be very easy to do and eliminate a lot of work.

Thanks for your help and suggestions.

Thank you for the useful response.

I will check the current flow through the wires (where they connect) while the control panel is activating the solenoid, making sure that it's 24V.

As a next test, is it possible to purchase stand-alone solenoids for valves, install them, and see if this fixes the problem? I'm not sure how the solenoids are physically attached to the top valve cover.

I thought that I had to buy a whole new valve to get a new solenoid but then did a Google on solenoids and got some web sites that sell solenoids for Hydro Rain valves.

Thanks again!

Good news!

I replaced the solenoids and the valves now work fine. I guess all 3 valves failed and, for the time being, the new solenoids have fixed the problem.

Thank you for all your assistance!

Good point.

Do you know where I can find/buy a Hydro Rain valve top? I managed to strip the solenoid socket on one of the valves (should have pulled out the plastic box in the ground around the valves first!) and now the new solenoid will not screw in properly and function. I'd sure like to avoid replacing the whole valve (in the ground). Thanks!