Intermittent Solenoids not opening

This has been frustration me since installation.

I have a Rachio3 and 5 zones with 1 Master. All but my Master solenoid is a 24VAC micro solenoid connected to 19mm tubing.

What I am experiencing is that when a zone starts the right solenoids buzz but don’t open. If I tap and sometimes bang the solenoid they open. This is intermittent. They have no issues closing. I have replaced solenoids with different brands and got the same result.

I have rewired the solenoids and changed from waterproof connectors to soldering in the hope that it was just poor connections. They work 1-2 times and then stopped opening without having to tap them.

I have also opened them and cleaned them (no visible grit). What I did notice was with the top off I tested opening the valve with Rachio and it buzzed but the pin wasn’t pulled up. It’s like its not strong enough.

Has anyone else had this issue?

Thanks in advance


Are you sure you have 24VAC solenoids? Can you take a picture?
What you are describing sounds very much like a DC solenoid being driven by an AC source.

Thanks for the fast response. Attached is a photo of one of them.

They are all AC.

Seems these are Australian valves, what power supply are you using with your controller, since original one is not compatible with 240v input voltage?

I replaced it with an Australian transformer that produces the same as the original.

Can you please provide a photo? If nothing else it may help others down under.
Also, how do you have it connected? Are you using the original barrel input, or hooking it up via 24VAC terminals?

Whoa! You genius. I was sold a 24VAC plug and looks like it’s 12VAC. I assumed because the box said 24 it was 24.

Thank you. I’ll go grab a replacement and hoping that fixes it. :hugs::pray::kissing_heart:

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