Author Topic: AWS Sensor Gone Bad - Can it be Fixed?  (Read 4511 times)

EarthBoxAdmin

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AWS Sensor Gone Bad - Can it be Fixed?
« on: July 07, 2017, 10:22:05 am »
Disclaimer: This post was originally posted by Hero Member, potatohead. This user is located in 9A Desert Southwest. This was originally posted on September 3, 2013.

I have had a sensor go bad for the first time on my AWS. I do have a filter hooked up to the spigot. This particular sensor was on its 3rd season. I must confess that I don't soak the sensors in vinegar when I remove them for the winter. I just hang it all up to dry and then store it all in a plastic tote indoors. I discovered one of my boxes dripping a few days ago. The box with the sensor out is fine and is not leaking anymore so I know the box is not at fault.  The sensor flunks the iced tea glass test (won't stop even with the glass full). My plan is to just cut it off the tubing and replace it with a new sensor. My question is, can the bad sensor be salvaged for future use? I've read on here about taking them apart, etc. but does that really work? What I am I looking for?   Is it worthwhile to take it apart or should I just throw it away?

EarthBoxAdmin

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Re: AWS Sensor Gone Bad - Can it be Fixed?
« Reply #1 on: July 07, 2017, 10:24:30 am »
Disclaimer: This post was originally posted by Hero Member, mjb8743. This user is located in Zone 7, South NJ, Garden State. This was originally posted on September 3, 2013.

The sensor can and should be cleaned periodically. Mineral deposits collect and impede the fragile functioning of the diaphragm.

You can take the sensor apart and clean all components by soaking in white vinegar, then a gentle brushing with a toothbrush. The orifice can be cleaned by inserting and rotating a small piece of wire while submerged in the vinegar. This is a good opportunity to examine the housing for any hairline cracks. A good magnifying glass would be handy here. A good rinsing should finish up.

Now the cautions:

--When disassembling, make a note of the placement/orientation of all components, especially the diaphragm.

--When reassembling, replace the diaphragm in the same orientation it was in originally.

--Insert the 3 screws sequentially, gradually tightening each in sequence. Do NOT fully tighten one, then the next, etc. Do not over-tighten or risk cracking the plastic housing.

Servicing the sensor is a doable project... one for those boring winter evenings when dreams of gardening haunt us.

Mickie

EarthBoxAdmin

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Re: AWS Sensor Gone Bad - Can it be Fixed?
« Reply #2 on: July 07, 2017, 10:26:24 am »
Disclaimer: This post was originally posted by Hero Member, movrshakr. This user is located in Zone 10a - near Cape Canaveral. This was originally posted on September 3, 2013.

gardendoc, here is a good opportunity for an instructional video....dis-assembly, cleaning, and reassembling an AWS sensor/valve.

Hey, you asked for suggestions!

EarthBoxAdmin

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Re: AWS Sensor Gone Bad - Can it be Fixed?
« Reply #3 on: July 07, 2017, 10:28:09 am »
Disclaimer: This post was originally posted by Hero Member, cc-fl. This user is located in Palm Beach Gardens, Florida - Zone 10. This was originally posted on September 3, 2013.

The AWS sensors are really easy to clean.  You just have to remember to keep the right side of the diaphragm pointed out.  Once you've removed the AWS from the line and removed the screws, a dental floss threader works great to clean the orifice (the loop threaders.)  You can work the threader back and forth to clean the entire surface.  Be gentle when you reassemble them so you don't strip the threads.  But if they aren't tight enough, the sensor doesn't operate properly.  When you have them apart, it's easy to see any mineral buildup and gently rub it off or scrub it with a toothbrush if necessary.

EarthBoxAdmin

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Re: AWS Sensor Gone Bad - Can it be Fixed?
« Reply #4 on: July 07, 2017, 10:29:02 am »
Disclaimer: This post was originally posted by Hero Member, potatohead. This user is located in 9A Desert Southwest. This was originally posted on September 3, 2013.

I am sure that mineral build up must have played a role here. We have extremely hard water.

I guess I will take this sensor apart and see what I can do with it and how long the procedure takes. If it takes more than an hour (not counting soaking time) it would probably be more cost effective to throw them out when they fail. I don't have a lot of time to spare unfortunately. I'll try it and see how it goes (when I have time, LOL). Thanks for all the responses; I really appreciate the help.

nitrous

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Re: AWS Sensor Gone Bad - Can it be Fixed? YES
« Reply #5 on: August 12, 2020, 05:08:11 pm »
CLR is a very good solution for hard mineral deposits.

On thing to do without disassembly is to use a syringe to flush the water inlet side of the system.  because the system is fixed open, there are a limited number of possibilities.  first is mineral deposits in the inlet side of the sensor.  The second would be a leaking diaphragm.  (the tell here would be water on the "dry" side of the system ie in the clear vinyl tube.  The third would be a crack on the dry side of the sensor or a poorly seated assembly.

I would start by simply blowing into the bell end of the sensor.  If water flow continues, I'd be looking at diaphragm or cracks... If the added pressure does solve the problem (ie stops the flow of water), the diaphragm may well be caked with mineral deposits on the water side of the sensor.  If you can't actually maintain added pressure when you blow into the bell, there is a leak and that is diaphragm crack (less likely if the dry side is still dry when in use). An other way to test this is to apply negative pressure on the water side of the sensor.... with the bell in a glass of water, check for water being drawn up the sensor tube.

To trouble shoot these systems, keep it simple and based on the way the sensor works. 
https://patents.google.com/patent/US6848483B1/en

Good luck!
Doug