Originally Posted by RV Pirate
Had (have) to the same problem in our Challenger. Had a little less than 1/2 in the fresh water tank when we hooked up at FW, when we were leaving I noticed we were over 2/3. Will check out the check valve, thanks!
Doing a little research online you'll find this is common across all manufacturers because of the 4-way valve (often made by Anderson). Due to hard water sometimes they will not open or close all the way, misdirecting the water. This can also cause low water pressure when connected to city water. I had this problem once. Since then I ALWAYS use a filter at the faucet before connecting my hose to my RV. I haven't had the problem since.
By the way, I "repaired" the the problem by switching the valve back and forth while under pressure and it cleared out the valve.