Sprinkler Valve Question

 Hi. I'm having a problem with the sprinkler valve on my next door
neighbor's system. It's an Irritrol 2711DPR valve...and it works fine
loosening the "manual" screw... but when using the controller, the
solenoid hums, a momentary gush of water comes out the sprinklers, then
cuts back to just a trickle. All the rest of the sprinklers in all
other zones work fine. Voltage is the same as at the other
valves...26.3 vac. Could this be dirt in the valve? If so, why would it
not affect performance on "manual"? If it is dirt, are Irritrol valves
easy to disassemble?...and anybody have any idea what a small tab on
the valve marked "<on-off>" does? Thanks in advance.

 On 6 Feb 2006 08:21:20 -0800, wanghu788@yahoo.com wrote:


Not familiar with that valve, but I've replaced several of mine over
the past 20 years or so.   Mine are all buried and I wouldn't waste
time repairing one when a new replacement is more cost effective in my
situation.

Regards,

Hal

 


Sounds to me as though you have a normally closed solenoid valve.  i.e.
unless the solenoid is energized the valve is closed.  The solenoid is
actually an electromagnet that when energized pulls the valve open allowing
the passage of water through the valve.  If the solenoid goes weak and opens
only partially then that would explain the trickle of water.  The momentary
gush may be that initially the solenoid develops enough magnetism to open
the valve all the way or most of the way, then the magnetism weakens and the
valve closes most of the way.

If the solenoid itself is easily replaced then that will probably solve the
problem.  If it is more cost effective to replace the entire valve then that
too would solve the problem.

Mr. Bill