# Clean Water Tank Overflow



## kaacee

I will try and explain the problem as best I can.....

When I fill the clean water tank, water escapes both from the overflow pipe which is situated in the top of the tank and from the round screw in type tank access cap also in the top of the tank. 

This in itself seems a little odd because normally (I think), the overflow pipe is situated on the side of the tanks similiar to the water tanks found in the loft etc.

Now obviously, when I see the overflow running I shut off the water tap, water flows out of the overflow until it levels out just below the overflow outlet,which is as far as I can tell, level with the screw cap outlet, but what concerns me, is the water that escapes via the "inspection" screw type cap.

It would appear, water can only escape from the overflow when the level reaches the very top of the tank. 

Should this happen and if not, how do I resolve the issue, the rubber seal on the cap appears to be in good condition and the cap screws in securely. Would a new seal maybe help?.

My main concern is although the tank is underslung, the water escaping from the cap could be blown back inside the hatch and maybe wet the floor or underneath wooden structure.

Sorry to be so long winded but I hope this explains the problem. Any help greatly appreciated.

Keith


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## zappy61

Hi Keith,
I don't think the water should be coming out of the inspection cap. I would remove it and check that the rubber seal is fitted correctly and not twisted when you screw it back on.

Graham


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## kaacee

zappy61 said:


> Hi Keith,
> I don't think the water should be coming out of the inspection cap. I would remove it and check that the rubber seal is fitted correctly and not twisted when you screw it back on.
> 
> Graham


Thanks Graham, the rubber O ring looks fine but obviously somethings amiss because I agree, water should not come out of there.

Maybe have a word with Swift see what they say.

Keith


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## peterandirene

My Starspirit has the same system. If I fill from a hose connected to the outside point the overflow runs when the water is about 1 inch from the top of the tank. I have never had water coming out of the inspection hole.

I assume that you are not switching the pump to ext and are taking water on from a tap. Try reducing the flow a bit. 

Have you thought about shortening the overflow pipe?

I rarely use the external connection these days as the tank is very close to the hab door. I just remove the inspection hatch and stick the hose directly into the tank to fill. 

If I am not near a water tap I fill a collapsible carrier (20 litres I think) and pour it in through the inspection hatch. Have to say though that we do not use a lot of water generally and this is quicker than moving the van to a water point.

Peter


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## mandyandandy

We have same system and nothing out of inspection hole but we do loose quite a bit from overflow when travelling along, which really bugs him :roll: 

Mandy


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## kaacee

peterandirene said:


> My Starspirit has the same system. If I fill from a hose connected to the outside point the overflow runs when the water is about 1 inch from the top of the tank. I have never had water coming out of the inspection hole.
> 
> I assume that you are not switching the pump to ext and are taking water on from a tap. Try reducing the flow a bit.
> 
> Have you thought about shortening the overflow pipe?
> 
> I rarely use the external connection these days as the tank is very close to the hab door. I just remove the inspection hatch and stick the hose directly into the tank to fill.
> 
> If I am not near a water tap I fill a collapsible carrier (20 litres I think) and pour it in through the inspection hatch. Have to say though that we do not use a lot of water generally and this is quicker than moving the van to a water point.
> 
> Peter


Peter, Not sure what you mean by "I assume that you are not switching the pump to ext".

I have reduced the flow from the tap which incidently is connected via a Heoswater fitting but it still seeps through the hatch. The overflow pipe appears to be at the same level as the inspection hatch, so I have lengthened it in order for the water to overflow approx 1" lower than the inspection hatch. This will hopefully work but I have not tried it yet.

Will report back with results.

Thank you all for your input, much appreciated.

Keith


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## Kev1

and you think you have problems!!!!!!!!
lol
The filler cap on our Hobby 750

appears to be slightly below where the pipe enters the top of the tank inside the vehicle.

i.e. water has to run up hill.
The only easy way to fill is to tip the vehicle slightly on it's side.

So I am feeding Sue up so she can lift the vehcile.
Fed up with trying to spend ages filling and more water running out than in.

Kev & the muscle bound Sue


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## peterandirene

Keith

On the zig unit I have a recker switch for the pump, INT for use on taps etc and EXT to suck water from a container through the external water filler into the tank. I was wondering if you were filling from a tap AND switching to EXT. 

When you say "lengthened" do you mean "shortened"? My overflow is a vertical pipe inside the tank.

Peter


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## jiwawa

My system is different - internal tank - so I'm just guessing here.

It's possible that if the pressure is too high AND the inspection hatch cover isn't properly seated, water could end up outside of the inspection hole.

Our cap on top of the tank was _apparently_ tight in - but it wasn't, and on travelling the water splashed around and quite a bit ended up on the floor.

I used a bit more muscle power on the cap and no more problem. Heaven knows how I'll get it off again!


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## cabby

In theory, the overflow pipe should have a loop to raise it higher than the tank level to stop it syphoning out. If yours comes out of the top of the tank then it will need a lower loop than out of the side.
As to leaking from the top cap, then it is not tight enough or it needs a little sealant to prevent this happening.remove cap half way before applying.
Have you looked on the Swift/Autocruise forum to see if it has been mentioned on there.
you should hear a gurgling sound of the air being forced out
when the tank is virtually full and is about to overflow, before it starts showing from the overflow pipe, 

cabby


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## kaacee

peterandirene said:


> Keith
> 
> On the zig unit I have a recker switch for the pump, INT for use on taps etc and EXT to suck water from a container through the external water filler into the tank. I was wondering if you were filling from a tap AND switching to EXT.
> 
> When you say "lengthened" do you mean "shortened"? My overflow is a vertical pipe inside the tank.
> 
> Peter


Peter,

I dont have the switch you refer to and my overflow pipe is outside the tank and enters into the top of the tank for approx 0.5" which is level with the inspection cap, so I have now lenghthened this to approx. 1" in order for the water to exit via the overflow before it reaches the inspection cap. Hope this makes sense.

Keith


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## kaacee

JWW said:


> My system is different - internal tank - so I'm just guessing here.
> 
> It's possible that if the pressure is too high AND the inspection hatch cover isn't properly seated, water could end up outside of the inspection hole.
> 
> Our cap on top of the tank was _apparently_ tight in - but it wasn't, and on travelling the water splashed around and quite a bit ended up on the floor.
> 
> I used a bit more muscle power on the cap and no more problem. Heaven knows how I'll get it off again!


JWW,

When I tighten the cap it is quite difficult to remove it again, so I am presuming it is not the tightness or lack of that is causing the problem.

Keith


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## kaacee

cabby said:


> In theory, the overflow pipe should have a loop to raise it higher than the tank level to stop it syphoning out. If yours comes out of the top of the tank then it will need a lower loop than out of the side.
> As to leaking from the top cap, then it is not tight enough or it needs a little sealant to prevent this happening.remove cap half way before applying.
> Have you looked on the Swift/Autocruise forum to see if it has been mentioned on there.
> you should hear a gurgling sound of the air being forced out
> when the tank is virtually full and is about to overflow, before it starts showing from the overflow pipe,
> 
> cabby


cabby,

Not sure what you mean by a "loop" (please excuse ignorance), the overflow pipe comes out of the top of the tank and then down the side of it to drain away.

I have mentioned it on Swift forum but no response as of yet.

Next time I fill, I will ask SWMBO to listen carefully for any gurgling noises.

Keith


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## cabby

reading your comments, I assume you have lowered the overflow pipe into the tank slightly to improve the system, however if the pipe comes out of the top of the tank it will make no difference.
the loop is where the pipe is raised above the tank level to stop it syphoning out when you go round corners etc.so the further down you push the pipe into the tank the more likely it will happen.  
It will not matter how tight you do the cap up if there is an air gap which will allow water to escape, this is why I said a sealant is best.
Undo the cap halfway apply sealant and slowly tighten, but not all the way or you will squeeze the sealant out.Please choose your sealant wisely.

cabby


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## kaacee

cabby said:


> reading your comments, I assume you have lowered the overflow pipe into the tank slightly to improve the system, however if the pipe comes out of the top of the tank it will make no difference.
> the loop is where the pipe is raised above the tank level to stop it syphoning out when you go round corners etc.so the further down you push the pipe into the tank the more likely it will happen.
> It will not matter how tight you do the cap up if there is an air gap which will allow water to escape, this is why I said a sealant is best.
> Undo the cap halfway apply sealant and slowly tighten, but not all the way or you will squeeze the sealant out.Please choose your sealant wisely.
> 
> cabby


cabby.

Thank you for your patience, yes I did think that lowering the overflow pipe would not resolve the situation and it does look like sealant may indeed be the answer, any reccommendation of the correct sealant would be very much appreciated.

Keith


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## TR5

I presume that as your overflow comes out of the top of the tank, then turns towards the ground, it needs to overfill to force a syphon, until below the level of the internal section of the pipe.

Try a fine smear of vaselene on the thread of the inspection door, which may help to tighten (and remove) more easily.

You could also use a piece of say 1.5" sq timber, long enough to give ease of use, and cut a slot in it to fit over the centre raised portion of the inspection door, to make it easier to secure and loosen.

HTH.

TR5


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## cabby

Tr5 makes a very good point there about the wood, however do rember that it is a plastic cap, with plastic threads.
As to which sealant, I would go to a plumbers shop/outlet and get a product from them, do not try the tape thats no good.
let us know what you finish up with.

cabby


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## kaacee

TR5 & cabby,

Just to update, Vaseline was the answer, applied a thin coat and tightened hatch with piece of wood as suggested, not excessively tight but enough to seal lid and bingo, filled up and no leaks just via the overflow as it should be,

Many, many thanks to you all for your assistance in resolving this issue. Not a mind blowing problem I know, but nice to know it now works as it should.

Keith


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