On Board Water Tank (1 Viewer)

[Silver-Fox]

More help required from you good people and knowledgeable beings

Our onboard fresh water tank keeps hopping from 100% to 75% but never drops below 75% even when empty.
Question is how easy would it be to investigate the problem as in is it a float similar to a petrol tank?

The tanks has two large black bungs I tried to undo but wouldn't shift. Are these screwed into place?
It also has a fitting with several cables going into it, Im guessing these go to the float?

Any pointers gratefully received.
Ohh and it did work ok a while back

T i A

 

[EuroTrotters]

Can you get your hand inside?.

It could be the sensors want cleaning. Never heard of floats!

 

[Gellyneck]

We've got a similar problem with our Auto-trail and worse so on the grey water tank.
Believe there are a number of sensors (4\5?) in the tanks which correspond to the %ages on the panel.
I've cleaned both tanks a couple of times but it just keeps coming back so now tend to ignore the readings.
Best guess what we've put in versus what we've used.

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[Rockcrawler]

My guess would definitely be sensors are gunked up and need cleaning

Ah note to self read the question properly !!!!

Thought it was the waste tank but could still be the sensors that have furred up

 

[EuroTrotters]

Similar to this

 

[EuroTrotters]

My guess would definitely be sensors are gunked up and need cleaning

Yes, never had one fail but could be

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[Lenny HB]

It is not a float it will probably be a sensor with 4 stainless steel probes, If the bungs are about 5" dia they are probably the inspection hatches and should unscrew often very tight. Once you get a bung out you should be able to remove the sensor then soak it in a dilution of hot white wine vinegar to remove any calcium build up with any luck will cure the problem.

If that doesn't work probably a duff sensor I've had them fail when just a few months old.

 

[WillH]

Just ignore the readout, after a few trips you'll get to know how much you use and when to top up.

 

[Silver-Fox]

Just ignore the readout, after a few trips you'll get to know how much you use and when to top up.

We've been doing that but if I use a watering can to top up Im never sure how much I need as she doesn't fill easily.
We use the water available differently on different trips so not consistent with usage

It is not a float it will probably be a sensor with 4 stainless steel probes, If the bungs are about 5" dia they are probably the inspection hatches and should unscrew often very tight

Yes around 5" dia I did try to undo them, we have two, they are as tight as hell
So long as I know they unscrew ill use my bigger tools on them

Thanks

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[Lenny HB]

Yes around 5" dia I did try to undo them, we have two, they are as tight as hell
So long as I know they unscrew ill use my bigger tools on them

Thanks

Nothing to do with me if you break them.
Post a pic then we may be able to confirm.

 

[Silver-Fox]

Nothing to do with me if you break them.
Post a pic then we may be able to confirm.

Will have to see if I can get some pics over the weekend as she is in storage.

The bungs have "fins" for want of a better word on the top.

Probably never been undone since built

 

[Lenny HB]

Will have to see if I can get some pics over the weekend as she is in storage.

The bungs have "fins" for want of a better word on the top.

Probably never been undone since built

Probably unscrew then.

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[tonyidle]

The bungs will unscrew - the rubber sealing washer sticks to them and the tank so once moved they come off easily. They are very robust. Use a piece of wood as a drift. Place it against a 'fin' then hit it lightly with a heavy hammer. Do the same with the fin diametrically opposite. It will unscrew. The 'sensor' is 5 stainless rods as pictured above. One rod goes close to the bottom of the tank and is the 'common'. The other rods are set (nominally) at 1/4, 1/2, 3/4, and full. When the appropriate rod is connected to the Common rod by water your gauge reads the level at that point. You will probably understand from the above that, for example, a reading of 1/2 means that the water level is somewhere between 1/2 and 3/4. 1/4 means somewhere between 1/4 and 1/2. When the level has dropped only just below a rod movement of the vehicle (and therefore the water) can cause the gauge to move between two readings.

 

[WillH]

I only use watering can and find one a day usually suffices, an occasional extra can if we do a lot of washing up.

 

[Silver-Fox]

@tonyidle excellent description of the workings and the bung I will probably use my pipe wrench with the jaws fully open and "inserted " across the bung and at 90 deg to it.
I have a bit of an aversion to hitting plastic stuff

I only use watering can and find one a day usually suffices, an occasional extra can if we do a lot of washing up.

We don't use sites that often and still getting to grips where to find water etc being relative newbies.
I was talking to a guy that uses the wild camping app and must say it was impressive with all the info on there i.e. places to stop, toilets etc.

Might just sign up for the full Monty think its around £25

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[WillH]

We are in Scotland and find most cemeteries have water, as do harbours. In a pinch we've taken water from a fast flowing burn.

 

[TCG]

Put some fenwicks tank Cleaner in and all will be well, we stick a small amount in every time we empty and all is well

 

[Silver-Fox]

Put some fenwicks tank Cleaner in and all will be well, we stick a small amount in every time we empty and all is well

Thanks but Im going to have to take it apart its in my DNA to see whats what

Ill vacuum out the bottom of the tank as well while I'm at it

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[Minxy]

Thanks but Im going to have to take it apart its in my DNA to see whats what

Ill vacuum out the bottom of the tank as well while I'm at it

Will you fit in there????

 

[JFD]

Hate to disagree with anyone on this forum, but hitting the fins on the cap may well lead to snapped fins! You can buy special tools to undo stubborn lids like this, called BOA strap wrenches - they are not expensive, probably less than a replacement lid! Have a look on Amazon, and your local tool store may we'll sell them.

 

[Silver-Fox]

Will you fit in there????

Highly unlikely

Lets just say I'm well built with big bones

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[DanielFord]

You need to clean the prongs. Get a green scourer, open the access panel, and feel up inside, there are 4 prongs of varying length, they will all be calcified. Now take the aforementioned green scourer and clean off all the calcium from the prongs. The water reading will be accurate for at least 2 weeks!

 

[two]

Why try to remove the 'big bung'? The sensor should be removable from the top of the tank and be much easier to clean that way.

 

[Minxy]

Is the cap something like this?

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[Minxy]

Highly unlikely

Lets just say I'm well built with big bones

So you're quite f*t ... fill in the middle letter (a or i) as appropriate!

 

[MitchandJenny]

Our Autotrail had the same problem.
I had the stainless steel sensor prongs, that fit into the waste tank, renewed and all was well for a few trips, then it failed again, so reached up over the chassis and disconnected the plug that feeds the tanks sensors.
I couldn't stand the buzzer, that warns of a full waste tank , going off regularly.
Bad design. But you could try the Fenwicks cleaner route or Cola.
My fresh water tank works ok and I know when the waste is getting full, cos the sink drains work slower.
We "live with it" and just enjoy life.
Taking the large drain caps off can cause more problems than it solves.
But good luck with whatever you decide to do.
Mitch.

 

[Lenny HB]

Why try to remove the 'big bung'? The sensor should be removable from the top of the tank and be much easier to clean that way.

Yes it is removable from the top of the tank but you need to undo the nut that holds it in place from inside the tank.

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[Silver-Fox]

A quick update

It would appear I jumped the gun somewhat.
Due to my prudent continuous topping up of said water tank I haven’t let the level fall more than 75%

I have found the main drain tap and emptying the tank for maintenance

I’ve tried to undo the bungs but think I need the special tool or I’ll have to make one.
Any ideas where I can buy one at reasonable cost?

This is the bung, b****r it put the pic at the top

Thanks

 

[Silver-Fox]

So you're quite f*t ... fill in the middle letter (a or i) as appropriate!

I like to think I’m fit and in winter warm mode at the mo

I don’t have a six pack more a “rounded” physique

I can still see William without the aid of a mirror so alls good
Or maybe I’m well blessed

 

[Lenny HB]

Never seen a tool for the job, a pice of wood with a couple of smaller blocks screwed to it should work.

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