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Sunday, July 10th 2011, 11:20pm

Nelson 7900 series valve staying on PLEASE HELP!!!

6 zone system. Zone 1 stopped working while the rest still are. I checked the wiring in the control box. It appears to be good. I replaced the solenoid for zone 1 and the valve opened. Now, zone 1 stays on continually whether the system is on or not. It continues running even if another zone starts. I can hear the solenoid working so I know it is getting power. I took the valve apart to look for dirt or rocks and didn't find anything. Please HELP as there is not enough beer to make me feel better about this situation! :(


Supreme Member

Posts: 493

Location: Seattle


Monday, July 11th 2011, 12:21am

Are you sure you got the right solenoid for the replacement? Look at the old one vs the new one and make sure they are exactly the same. Did you loose the o-ring ( if this solenoid has it) ?


Thursday, July 14th 2011, 12:17pm

The solenoid is not exactlythe same. The system is 7 or 8 years old and our locale retailers didn't carry exactly what I replaced. I was told to order on-line to replace the identical one. does it really make a difference even if you can hear the solenoid working when you first put power to it?


Supreme Member

Posts: 5,223

Location: Metro NYC


Thursday, July 14th 2011, 1:09pm

why not get a spare valve or two?


Thursday, July 14th 2011, 1:24pm

I do have a Hunter valve I bought at Home Depot when I got the solenoid's but didn't want to tear into the system if I didn't have to. Getting to that point though, just to have a working system again. Seems everyone is out of stock on the exact match solenoid from Nelson or Signature now.


Supreme Member

Posts: 5,223

Location: Metro NYC


Thursday, July 14th 2011, 2:31pm

That's why I posted a link for the entire 7900-series valve. That it's a flow-control model should make no difference. These things are hard to get now, so you grab what you can.


Thursday, July 14th 2011, 2:47pm

thanks for the help and advise. I will go and order some on-line to replace and have them on hand. Thanks

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