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2marshall8

Starting Member

1

Sunday, August 28th 2016, 10:56am

Water Pressure Low in single Zone

I worked about 3 yesterday on this and have almost given up. I feel like I've done everything but replace the Rainjet RJ711 3/4" Valve. The issue is as follows:

When I turn on this particular zone there's not enough pressure to popup the sprinkler heads. The way to get the pressure to work is by unscrewing the Solenoid just far enough where it begins to leak and than they all popup. Thus I began my investigation below

I have a single zone of 3 sprinklers heads fed by a Rainjet RJ711 3/4" Valve. I have made sure the Flow Control knozzle is turned all the way counter-clockwise to make sure the water has an open path to the sprinklers, I have Removed the Housing over the Diaphragm and verified that there wasn't any debris as well as made sure that the Diaphragm was intact. I also verified that there weren't any cracks or issues with the parts inside the housing where the Diaphragm is kept. I have replaced the Solenoid as well. I know the controller is working because I hear the water kick on for this zone as I manually activate it from the control panel

I know howto get the pressure to the sprinklers using this Solenoid twist method but this isn't a long term solution. What do you recommend I try?



thanks

Wet_Boots

Supreme Member

Posts: 5,223

Location: Metro NYC

2

Sunday, August 28th 2016, 1:09pm

You need to completely rebuild that mess. Antisyphon valves need to be above grade and higher in elevation than any pipe or sprinkler that they feed. What you have in the photo is a health hazard. The top valve is a newer design, and worth keeping. The two with the Rain Jet name can be saved for parts, but don't bother putting them back into service.

mrfixit

Moderator

Posts: 2,153

Location: USA

3

Sunday, August 28th 2016, 8:49pm

Boots wasn't wearing his glasses when he looked at your picture. Easily done.

The top and bottom valves are the same. The valve in the middle you can get working again by swapping out the diaphragm

It looks like somone moved the solenoid from the bottom valve to the middle valve.

Anywho. Yep your ASV's are below grade. Will they work? Yes. Is it up to code? No.

Wet_Boots

Supreme Member

Posts: 5,223

Location: Metro NYC

4

Monday, August 29th 2016, 2:45am

Yep, glasses off. :thumbup: I wouldn't claim the old-design valve can never be put back in service, but that the new design will be more trouble-free, and for the ten bucks a replacement valve might sell for, compared to five bucks for the diaphragm assembly, go ahead and spend the extra it takes to have all the valves be of the new design.

marshall28

Unregistered

5

Tuesday, August 30th 2016, 9:31am

Boots wasn't wearing his glasses when he looked at your picture. Easily done.

The top and bottom valves are the same. The valve in the middle you can get working again by swapping out the diaphragm

It looks like somone moved the solenoid from the bottom valve to the middle valve.

Anywho. Yep your ASV's are below grade. Will they work? Yes. Is it up to code? No.

Even though the unit looks to be in perfect condition, could this still be the issue?

Wet_Boots

Supreme Member

Posts: 5,223

Location: Metro NYC

6

Tuesday, August 30th 2016, 10:27am

You should just rebuild the manifold, and work from there. There is no exact answer to your question. The usual failure mode for the old type of valve, the RainJet 711, is to not even open at all.

marshall288

Unregistered

7

Tuesday, August 30th 2016, 5:26pm

You should just rebuild the manifold, and work from there. There is no exact answer to your question. The usual failure mode for the old type of valve, the RainJet 711, is to not even open at all.

Rebuild the manifold? So replace the entire valve casing? To your 2nd statement regarding the failure mode of the RainJet 711, are you saying what I'm experiencing isn't normal?

thank guys :)

Wet_Boots

Supreme Member

Posts: 5,223

Location: Metro NYC

8

Tuesday, August 30th 2016, 6:15pm

Rebuilding the manifold isn't a ton of work or money, and while you're doing it you can swap the Rain Jet 711 valve for another Lawn Genie antisyphon valve, and enjoy the result of matched valves that are less likely to be a problem.


The 711 valve is subject to problems you will not be able to get a part for. You can replace a diaphragm assembly in that valve. I do it all the time, in an old system where every valve is a 711, and I'm keeping it all of a kind.

This post has been edited 1 times, last edit by "Wet_Boots" (Aug 30th 2016, 6:29pm)


marshall777

Unregistered

9

Tuesday, August 30th 2016, 10:41pm

Rebuilding the manifold isn't a ton of work or money, and while you're doing it you can swap the Rain Jet 711 valve for another Lawn Genie antisyphon valve, and enjoy the result of matched valves that are less likely to be a problem.


The 711 valve is subject to problems you will not be able to get a part for. You can replace a diaphragm assembly in that valve. I do it all the time, in an old system where every valve is a 711, and I'm keeping it all of a kind.


So you got me wondering if I should first replace the Diagphram and see it fixes it, and if that doesn't work, replace the entire RainJet 711 with a Lawn Genie?. hmm...

mrfixit

Moderator

Posts: 2,153

Location: USA

10

Wednesday, August 31st 2016, 1:48am

Rebuilding the manifold isn't a ton of work or money, and while you're doing it you can swap the Rain Jet 711 valve for another Lawn Genie antisyphon valve, and enjoy the result of matched valves that are less likely to be a problem.


The 711 valve is subject to problems you will not be able to get a part for. You can replace a diaphragm assembly in that valve. I do it all the time, in an old system where every valve is a 711, and I'm keeping it all of a kind.



What parts are you saying he wont be able to get? You made that up didn't you.

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