City Water/Fresh Tank connection?

[AZCamper1]

On our '17 14DBS we were hooked to a city water connection and in the morning it looked like water was coming out of the fresh tank vent overflowing onto the ground!  We found that the fresh tank was completely full.  I have had no chance to look and see what's up, but may have time today to do so.  Anyone else experience this?  Thanks for any help!

[DavidM]

There may be a check valve after the pump that keeps water from backflowing into the fresh water tank that is bad. Or maybe they rely in the internal check valve in the pump to do that and it is bad. Easy to buy a valve replacement kit at an RV or marine supply shop and fix it if it is the pump. If it is a separate check valve, either replace or take apart and see what is wrong.

David

[charliem]

Unless LL/Thor changed from 2014 there is no extra check valve. They rely on the check valve internal to the pump. A leaky valve will also manifest itself in the pump cycling occasionally at night if the pump is left energized. Replacement/repair of the valve is simple with replacement parts from the pump manufacturer, typically ShurFlo. Verify the pump model from the name plate and find parts via the internet. The whole job takes less than an hour if you're really slow. 

[AZCamper1]

Thank you both, makes perfect sense to me.
As I often tell others, "I may not be good, but I'm slow."  So I will test that time limit!!