# water system



## cheshiregordon (Sep 24, 2011)

sorry if this has been raised before - I've replaced the pump on my Hymer B640 and in the process noticed that the tank has two pipes, one from the pump and the other looks like some sort of return? Both feed from the same screw cap on the tank and run parallel before disappearing behind the tank. 
The return one (as I call it) looks quite dark as if the inside is in need of sanitising. 
Does anyone know if I'm on the right track with this? or have a schematic of the water system?

If it's a return how do I clean it?


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## Bob45 (Jan 22, 2007)

Not entirely sure but I think one delivers cold water to taps and hot water heater and the other one to flush the loo or maybe another combination of those three.
As for cleaning there are loads of threads on cleaning water systems here.
Bob


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## cheshiregordon (Sep 24, 2011)

I perhaps should have added that the "return pipe" doesn't actual enter the tank but simply connects to the screw cap thus allowing any water to pass back into the tank (but not picking up any water)

Could it be an overflow pipe??


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## charlieivan (Apr 25, 2006)

I think it may well be a vent pipe. This will allow air into the tank when the pump is in use otherwise there would be a tendency to draw a vacuum in the tank and the pump would struggle to move any water.


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## Bob45 (Jan 22, 2007)

Vent pipe it is!

Bob


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## cheshiregordon (Sep 24, 2011)

*Cleaning Vent pipe?*

Thanks chaps - I suppose that this needs to be taken off and cleaned separately as its unlikely to touched by cleaning fluid when cleaning the tanks and pipes etc.


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