Fresh water tank filled - from city water connection

Blueespy

On a four month trip and on two occasions, I’ve discovered our fresh water tank is full.  I haven’t filled it - on this trip we just hook up to Park water, but again on two occasions, I’ve seen water spilling from the fresh water tank fill valve.  Puzzling, so I reached out to nuCamp and they think it’s a pump issue and if I could make a short detour on our trip, they could do an inspection.  Has anyone experienced this before?  Also, curious where is the water pump.  I read it’s a pretty easy replacement but darn I’m not sure where it is.  We have a 2019 t@b 400 BDL.

Sharon_is_SAM

The pump is under the bed.  IIRC there is a check valve in the pump.  If that failed water will enter the intake side of the pump and fill the tank. The water spill you are seeing is likely from the fresh tank vent which acts as an overflow when the tank is over filled.  Are you using a pressure regulator?

Blueespy

Yes, pressure regulators on both fresh water fill and on our black line that we use to flush the black tank.  My fresh tank is currently full (we are boon docking on the ALCAN) but still no water spill except on just two occasions.  We have a few other minor things (black plastic trim on the bathroom door that has cracked) that nuCamp doesn’t use anymore but uses aluminum (we’ll have them replace it) and a front window that after we have it open and then close it, the left side (looking out) doesn’t close even and I have to go outside and with gentle pressures, push down on the top and it sort of reseats.  They said they can do some sort of test to see if the water pump valve is faulty.  Thank you for the info.

ScottG

This same problem has come up a few other times. Assuming all your Nautilus settings are correct (I'm not even sure if you have a Nautilus on a 2019...) it's almost certainly a failed check valve inside the pump.