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Understanding tank sensors

July 26, 2016, 01:04:06 pm

My grey tank sensor seems to be dead, so I am trying to figure out how the sensors work. I understand how to read the tank level display on my Audit 5T9. I am about to tear the utility bay apart and try cleaning the grey tank sensor(s). Are there multiple sensors on each tank? Are they mounted near the bottom of the tank? I was hoping for an article on beamalarm.com or here but haven't found anything.

Thanks, Royce

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Re: Understanding tank sensors

Reply #1 – July 26, 2016, 01:31:05 pm

I believe yours are the same as ours, a screw-in pressure transducer.  They will be screwed into a short riser, most likely have a black plastic hex head with 2 wires coming off (hex-head item in photo below; that one is our fresh tank)


Grey and black tank sensors are likely behind the wall of the utility bay.

The transducers do go bad after a few years.  If you are getting zero reading this is likely what happened.

The way they work is pressure on the transducer creates a voltage level which is then read by the Audit computer.  The system is told what voltage represents empty and what voltage is full during calibration.

It has generally been recommended that if you replace one sensor, replace all since the instructions state you have to recalibrate the Audit if you replace any sensor. 

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Re: Understanding tank sensors

Reply #2 – July 26, 2016, 02:03:08 pm

Royce, your 2001 is probably like mine. Here is a picture of what is behind the wall in the service bay.  The two pressure transducers were removed and replaced with white PVC plugs. I went to a SeeLevel system.  We like it a lot more.  The fresh water transducer is in the water manifold bay and still worked.  The gray and black water transducers were all plugged up with well, stuff.  I made no effort to clean them.  But if you replace them that is where they go.

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Re: Understanding tank sensors

Reply #3 – July 26, 2016, 05:00:46 pm

Does anyone have a manufacturer and part number for these transducers?  Thanks very much.
2002 U320 3620

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Re: Understanding tank sensors

Reply #4 – July 26, 2016, 08:16:52 pm

I pulled the black sensor out and cleaned it up a while back - 2 to 3 months ago - It read correctly for a while then back to showing about 1/8th of a tank from empty.  I have decided to live with it until we get back to Houston/Nac. and then replace the black and gray tank sensors.  our black tank sensor is behind the Wet bay panel right before the electric gate valve, the gray behind the water manifold and the fresh sensor is in the fresh water pump area.  Our Black sensor is kind of a pain to get to but once the panel is off it's easy to remove and replace.

Good luck... 

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Re: Understanding tank sensors

Reply #5 – July 26, 2016, 08:51:23 pm

Roger, what's the fan on the right?

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Re: Understanding tank sensors

Reply #6 – July 26, 2016, 08:53:04 pm

Quote from: fouroureye – July 26, 2016, 08:51:23 pm

Roger, what's the fan on the right?

AquaHot wet bay heating

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Re: Understanding tank sensors

Reply #7 – July 26, 2016, 08:55:19 pm

It is an AquaHot heat exchanger.  There are two of them in the bay where the fresh/black/gray tanks are, one one each side. They have their own thermostat in the bay that turns them on when it gets cold.

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Re: Understanding tank sensors

Reply #8 – July 26, 2016, 09:03:45 pm

Barry Beam says, "I ordered one [on] 3/10/11 and Foretravels part number was 5001005001 $45.00"  Might be more now.

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Re: Understanding tank sensors

Reply #9 – July 28, 2016, 02:41:00 pm

Thanks very much

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Re: Understanding tank sensors

Reply #10 – July 28, 2016, 03:05:23 pm

Thanks to everyone for help on this. I read an older thread that indicated $70 each from FT. I think I will try cleaning it first.

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