Losing fresh water into grey water tank

[Ken enns]

I have a strange problem. I have a 2007 Holiday Rambler 38 PDQ. I recently went out for a week and encountered a problem where my fresh water tank somehow drained most of it's contents into the grey water tank. It is my understanding that the fresh water can only enter the grey water tank though a drain. There is no fresh water leaking anywhere and the water pump only does an occasional burp so as to maintain pressure. I drained the grey water tank and refilled the fresh water and it has now somehow transferred most of the fresh water again to the grey water tank. I have spoken to a couple of RV repair techs and the consensus is that this is not common or even possible . Has anyone encountered a similar situation?

 

[Texas Clodhopper]

I had a similar instance several years ago and found it was the vacuum breaker/check valve for the shower water.

 

[Texas Clodhopper]

BTW, welcome to RVForums.com.

 

[Ken enns]

I had a similar instance several years ago and found it was the vacuum breaker/check valve for the shower water.

 

[Ken enns]

Can you tell me where this vacuum breaker is located?
Ken

 

[Kevin D Pem]

The pump won't run if you don't have a leak. Sounds good but even pump valves leak back into the fresh water tank at times. Any one of your taps can have a drip.
First thing I would blame is the human habit factor! Mostly due the volume of water lost to the gray water tank!

 

[Texas Clodhopper]

Can you tell me where this vacuum breaker is located?
Ken

Mine was on the shower water line. I recommend you call Forest River and ask them where it can be found.