Manually opening the valves won't turn on sprinklers

[CluelessinTexas]

Hi, I recently moved into a new house with a Rainbird sprinkler system. I turned it off when we had some heavy rain and now it won't go on again. By that I mean it cycles through the zones but no water comes out of the sprinklers. The rain sensor may or may not be bypassed (I took the top off and the disks out, not sure if that is enough).

I have done some research and talked to Rainbird tech support. At first I thought there was some electrical issue (eg wire from the controller) but when I try to turn on the valves manually the sprinklers won't come on either.
The valves are DV series and when I turn the little knob anti-clockwise water dribbles out. But nothing comes out of the sprinklers. This is for all the valves.

Is there something I am overlooking? Is the water somehow in sequence, ie should I open all the valves at once to test? Or am I not doing it right? I am puzzled why all 6 valves would suddenly stop working. Is there anything which would override the manual valve opening? I am pretty sure the water supply is on, the water keeps dribbling if I leave the valve open, until the underground box is full of water.

I know I will probably end up having to call someone in but first I want to try and get a good idea of what the issue is.
Any replies appreciated! Thanks.

 

[Mr_Pike]

Follow the wires from the rain sensor to the common wire of the clock (or to the clock itself) Remove them from the clock, or take them out of the common wire (reconnect common wire).

You may have a Master Valve that would still be closed therefore opening the zone valves manually (by loosening the solenoids) will not do anything.

Are there any wires connected to the M or MV lug on the clock?

 

[Sponsor]

 

[CluelessinTexas]

thanks

Thanks for the reply. I have now disconnected the rain sensor, there is an MV port but no wire connected.
One thing I did discover is a pressure vacuum breaker sheet in with my sprinkler documentation. I found it on the side of the house but I don''t dare play around with it too much. If this malfunctioned could it cut off the water supply? Just scrabbling around for answers here!

 

[Verdeboy]

If you really have manually opened your valves and no water is coming out, then you can be sure that the main is shut off at some point before your system.

I suppose the problem could be related to your pressure vacuum breaker.

Do your valves and PVB look like this:

If so, check #2 and #3 from the PVB diagram (your inlet and outlet) to see if they are closed.

 

[CluelessinTexas]

Thanks for the information. Actually one of the handles on the PVB is turned so it does look closed - *but* it is so tightly wrapped in insulation that I can be pretty sure it has always been this way, even when the system was working. I guess someone just fitted it backwards or something (like half the door handles and light switches in this house ).

 

[Mr_Pike]

So Dumb question, but did you actually see it running prior to this issue (since it is a new house)

You can check to see if the water is on at the PVB, by using a screwdriver to open one of the test port valves on the side of the unit. You likely won't hurt it. Inline with the port is open, perpendicular is closed.

Water will spray out of the port if the water is on.