Exterior Water Tanks Filling Whilst Connected to Mains Supply

[Tonykarter15]

I have just returned from holidays and during the trip, found a small issue relating to plumbing/ water tanks that I need to address.

I left home with my tanks 50% full at the start of the trip. Whilst travelling, i used the water pump to access the water during stops. At my first destination, i hooked up the main water supply to the van and then turned the water pump switch off.

Over the course of the next 48hrs, the two tanks filled to capacity with water dribbling out of the breather.

I assume that there must be some sort of non-return valve in the plumbing lines separating the main water inlet and the tanks- is this correct and where would I find it? Does anybody have any other ideas as to how this is occurring and what people have done to stop it from happening. I am considering relocating the incoming water supply to bypass the existing system merging it further away from the tanks but that is a big job if I don't need to.

 

[Drover]

There should be a non return valve at the pump, depending on pump it is normally at the inlet fitting......the quick and easy way if the pump is running okay would be to buy a John Guest non return valve ($20) and just fit it to the supply line just before the pump this will stop the mains from filling your tanks alternatively turn the tanks valves off................

Many of us have repositioned the mains supply from van wall to underneath to sort out possible leak problems, I even moved my pump to underneath and thereby removed 19 possible leak points from inside my van...............

 

[Tonykarter15]

thanks Drover. From the sounds of it, my thoughts about relocating the incoming mains position and plumbing is probably the best long term solution to the problem.

 

[Drover]

Relocating your mains won't fix the tank fill problem though.........if you look around on here you will find a blow by blow description, usually you only need a bit of alloy angle and can use the original piping and joiners......having a couple of John guest fittings in the spares box is handy.

This link is to my 14.44.3 thread which I'm sure has info about it...www.expandasdownunder.com/threads/drovers-14-44-3.4502/page-18

 

[Base23]

I am having the same problem with the water tanks being filled when connected to mains.
I though I had fixed it by adjusting the bypass valve in the water pump and that did work for a while but I had the problem again last weekend.
I am going to fit a john guest non return valve at the pump now and that should fix it for good.

 

[Drover]

If anyone pulls theirs down I'm betting a small bit of plastic drill swirl is the culprit, it wouldn't be very big just like a small bit of finger nail.

 

[Crusty181]

I have just returned from holidays and during the trip, found a small issue relating to plumbing/ water tanks that I need to address.

I left home with my tanks 50% full at the start of the trip. Whilst travelling, i used the water pump to access the water during stops. At my first destination, i hooked up the main water supply to the van and then turned the water pump switch off.

Over the course of the next 48hrs, the two tanks filled to capacity with water dribbling out of the breather.

I assume that there must be some sort of non-return valve in the plumbing lines separating the main water inlet and the tanks- is this correct and where would I find it? Does anybody have any other ideas as to how this is occurring and what people have done to stop it from happening. I am considering relocating the incoming water supply to bypass the existing system merging it further away from the tanks but that is a big job if I don't need to.

We had the same issue delivered from the factory, and like @Base23 they adjusted the the pump which fixed the problem, but i added a non return just to be sure. Hasnt been a problem since