Fresh Water Tank overflowing

[TerryT]

Hi, I have recently taken the plunge and bought a 2011 Swift Mondial Campervan on a Peugeot Boxer base, when flushing the tank it started leaking I think from the top under the insulation jacket. I think there should be a an overflow but can't see it and the leaking starts when it only registers 3/4 full , possibly the sensor is not correct and the tank is actually full and overflowing?
There is what looks like an overflow pipe but is on the water intake side not near the tank, I have hopefully attached photos,1st the tank with tap outlet, 2/3 pipework on other van water inlet side.

Appreciate any comments
Thanks

 

[Riverbankannie]

and
Water tank sensors are notoriously unreliable. The water is probably coming from the overflow.
To test it, you could drain into a bucket and see how much you have.
You can clean up the tank and sensors with a solution of citric acid - as you can imagine scale builds up. I tend to introduce the solution, drive around a few roundabouts and leave overnight before pulling through the taps and flushing with fresh water.

 

[TerryT]

and
Water tank sensors are notoriously unreliable. The water is probably coming from the overflow.
To test it, you could drain into a bucket and see how much you have.
You can clean up the tank and sensors with a solution of citric acid - as you can imagine scale builds up. I tend to introduce the solution, drive around a few roundabouts and leave overnight before pulling through the taps and flushing with fresh water.

Thanks,sounds like a good idea!