# RO/DI solenoid is making brutal noise



## mattdean (Oct 23, 2010)

So my RO/DI solenoid is making a brutal noise. A loud buzzing/vibration off and on. Sometimes for long periods of time and sometimes just a bit. It sounds like air in the piping or solenoid.

I have replaced the solenoid at least 2 or 3 times but the noise comes back after a short while. 

Any ideas? Really don't want to buy a new RO unit.


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## bc1281 (Feb 25, 2012)

Maybe your back flow preventer is shot.


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## wtac (Mar 17, 2006)

RO/DI solenoid...it should be making a solid clicking noise when energized/de-energized. A buzzing noise is usually from a failing float switch.

If it's the ASOV (auto shut off valve) where you will get a cyclical rapid to ceasing of "water hammering" in the RO lines, the check valve* (as bc1218 mentioned) or ASOV is failing or you suddenly have an increase of water pressure over 100PSI.

*the check valve is either a separate fitting between the RO product and ASOV or is integrated into the fitting of the RO product port.

HTH


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## mattdean (Oct 23, 2010)

I believe it is the ASOV. That seems to be where the noise is originating. I'll order another and hope that solves it. Thanks for the help!


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## bc1281 (Feb 25, 2012)

This happened to me about four times in four months. Each time I replaced the asov. It wasn't until I replaced my check valve that it finally stopped. If your going to order another part, maybe through in a check valve. Its worth the aggravation.


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## mattdean (Oct 23, 2010)

I've order an ASOV and Check Valve. Hope that does it. It's keeping my wife awake


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## wtac (Mar 17, 2006)

Yeah...when the water hammers from the ASOV cycling, it reminds me of the creaking sounds of old sea vessels/WW subarine movies.


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