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New Member


Tuesday, June 7th 2011, 9:52pm

Weathermatic Valves stay open

I have a sprinkler system that was installed in 1997, prior to my owning the home. All components (controller, sprinklers, valves) are Weathermatic. The valves, from what I can tell, are similar to the current 12000 series. They have solenoid # M 21E if that help at all. I have 5 zones and 2 of them stay on either partially or fully when the solenoids are not energized.

Should I try to replace the diaphragms in these 2 valves or just replace the valves (or all 5 of them) all together? Also, is the 12000 series a good, economical choice for my application since these valves have worked for approximately 13 years?



Supreme Member

Posts: 493

Location: Seattle


Tuesday, June 7th 2011, 11:28pm

More then likely if it's 2 valves stuck open than there is some kind of contamination in the system that damaged these valves
You can attempt to gut swap and flush out the of contamination. Though there may be more in the line to re-contaminate.

Also in my experience. The old black casing weathermatic square top valves ( Depending on the model) are not all compatible with the newer valves. Also the Screw holder ( the brass threaded section you see holding in the bolt) becomes loose to the plastic body casing..
I stopped attempting to gut swap these old to new valves a while ago because thew screw holder would just pop off after I replaced the valve, even tho the bolt was tight. The brass would just pop up from the plastic


Supreme Member

Posts: 5,294

Location: Metro NYC


Wednesday, June 8th 2011, 6:03am

Just for grins, remove the solenoid from a stuck valve, and see whether the plunger is free to move


New Member


Wednesday, June 8th 2011, 7:21pm

Solenoid Operation

I removed the plunger from the solenoids on 2 valves. One was a valve staying opened and the other is operational. Both plungers were free to move into and out of the solenoid coils equally well.

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