Fresh water level sensor (1 Viewer)

[Coverco]

My fresh water level sensor is not working intermittantly. I assume the probes need a good clean and wanted to remove the sensor to do it properly, having searched online I assumed that it would have a big nut inside the tank. I managed to bend my arm around and to my surprise have found that there is no nut, there feels to be cone of plastic which is part of the tank and the probes come out of the tip of the cone. The top of the sensor is a blue cylinder with wires coming out of it. I am at a loss as to how the sensor is attached to the tank, has anyone else got something similar. I can probably take some pictures inside the tank if required, any help appreciated.

 

[tonyidle]

It is screwed into a threaded hole in the top of the tank. It will unscrew ccw if you wear a rubber glove to help grip it.

 

[pappajohn]

If you get it working properly it won't work properly for long.
Waste of time...... When no water emerges from the tap there's no water in the tank... And you're going to have to fill it regardless of whether it runs dry or the sensors work properly.

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[Coverco]

Thanks Tony, I did try unscrewing it by hand but did not want to force it. I thought it must be something like that as the cone is obviously part of the tank. Will get the rubber gloves out tomorrow, if that does not work I have an oil filter clamp that might do the job.
We only bought this van in May, before that I had a 1995 Hymer and the water level sensors worked great. Like many things if you look after them they last a long time

 

[mitzimad]

when the waste tank is full the fresh is empty so dont need both

 

[Coverco]

when the waste tank is full the fresh is empty so dont need both

Nice idea but our fresh is 140l and the waste is 100l so no prize in this instance

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[LPB]

Citric acid is your friend.
Do a search, it does fix this problem,
Lloyd

 

[Gellyneck]

Waste of time cleaning the sensors.
They'll work for a week of two and then you're back to doing the exercise again.
As PJ says, nae water from the tap put more in!

 

[Coverco]

On my previous van the sensors worked perfectly with no maintenance for the 4 years we owned it .I will never subscribe to the defeatist attitude of "it is a waste of time" as a graduate engineer I will always fix the problem but thanks for your input

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[Northernraider]

Mine seem to work fine too

 

[Duck Truck]

we have a a tank with the sender unit recessed into a big screw off lid
Damned if I can get enought grip to undo it
Because it's between the floors the access hatch is tiny and i can't get anything in to
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any ideas

 

[pappajohn]

On my previous van the sensors worked perfectly with no maintenance for the 4 years we owned it .I will never subscribe to the defeatist attitude of "it is a waste of time" as a graduate engineer I will always fix the problem but thanks for your input

Perhaps, as a graduate engineer, you could design a system which actually works then sell the patent to the manufacturers.... I'm sure they would keep it on file as there's no profit in something which works faultlessly.

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[pappajohn]

Nice idea but our fresh is 140l and the waste is 100l so no prize in this instance

We'll there's your indicator.... When water emerges up the shower waste hole you have approx 40 ltrs left, less whatever you drank.

 

[pappajohn]

we have a a tank with the sender unit recessed into a big screw off lid
Damned if I can get enought grip to undo it
Because it's between the floors the access hatch is tiny and i can't get anything in to
add purchase
any ideas

Oil filter strap wrench.

 

[Lenny HB]

Keep the probes clean and the ones Hymer fit work quite well. Had 3 Hymers all been held in place by a nut on the inside.

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[TerryL]

Care about trying to unscrew it. The sensor block on my Swift is held down by three screws through the housing into the tank.

Unlike many, it's quite accessible through a trap in the floor.

 

[hilldweller]

I used a pan-scrub with the sensor in place. Improved it a lot but still the odd glitch.

 

[Robin McHood]

On my previous van the sensors worked perfectly with no maintenance for the 4 years we owned it .I will never subscribe to the defeatist attitude of "it is a waste of time" as a graduate engineer I will always fix the problem but thanks for your input

Agreed, we use capacitive sensors on several process tanks on board ship and they work fine for very long periods. Main problem in moho tanks seems to be the build up of limescale on the surface and unlike the sensors I use there is no simple way of recalibrating them externally so only cure is to descale them

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[Robin McHood]

I used a pan-scrub with the sensor in place. Improved it a lot but still the odd glitch.

Aye but should be careful how aggressive you are and be sure the sensor isnt a plated type. I've seen a few where the sensor surface is a thin metal film on a plastic base...

 

[Coverco]

It is strange how many differences there are on Hymers. The sensor is screwed in to a threaded moulding on top of my tank. Hard to unscrew but now working correctly.

 

[tonyidle]

There is another gotcha with the blue screw-in sensor used by (some) Hymers (and possibly others). It comprises stainless rods pushed into copper sleeves with wires soldered to the copper. A plastic moulding holds the whole lot in place and is itself filled with epoxy. In time water can creep up the rod and make contact with the copper which then corrodes causing an intermittent connection with the rod. The sensor is effectively scrap if this happens. This is what happened to mine. The giveaway was that affected rods could be easily pulled out of the cap.

There is a fix if you're handy & have a workshop but it's long-winded and boring and offered on a need-to-know basis .

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[Lenny HB]

It is strange how many differences there are on Hymers. The sensor is screwed in to a threaded moulding on top of my tank. Hard to unscrew but now working correctly.
View attachment 262314

Not seen one like that before, the ones in all our Hymers have had a nut on the inside.

 

[Duck Truck]

pappajohn
I have a chain strap one and it's not long enough
but it's given me something to think on
and i will give it a whirl

 

[hilldweller]

Aye but should be careful how aggressive you are and be sure the sensor isnt a plated type. I've seen a few where the sensor surface is a thin metal film on a plastic base...

Yes indeed. I am worried my metal prongs could have been plated but, what the hell, they weren't working properly anyway, they are now most of the time then for no reason it will give as low water warning when they is quite a lot left.

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[BusyBuilder]

Cleaned ours with lemon juice about 10 months ago, been working perfectly ever since.

 

[Duck Truck]

Chain strap won't work the cap is far too recessed
Stumped

 

[Coverco]

Chain strap won't work the cap is far too recessed
Stumped

Perhaps one of those rubber jar openers might work?
Amazon product ASIN B00F67TLFC

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[Duck Truck]

Hi coverco
Thanks mate
but the cap is recessed level with the tank and with almost no gap to insert anything
the cap has fins set into it
I have given them a bash with a length of wood and a rubber mallet. To no effect
i have poured a tiny amout of olive oil into the crack hopeing to lube the seal
still no effect

 

[Coverco]

A thin sheet of rubber or something like that is worth trying. I took the button off the top of my toilet cistern yesterday using a rubber glove, I put it on top and using the flat of my hand with a bit of pressure was able to turn it. If it goes in it will come out is my motto

 

[Duck Truck]

Tried that coverco
whoever put it in
they did it with a vengence

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