NEED HELP 2021 Passport 2900RL.

[CDRVing]

I’m hoping someone can help us. This is our first time out this year. When we hooked up the water my husband put some water into the water tank and then moved the hose over to the city water valve. The water tank filled all the way up! I’m hearing what sounds like a leak where there water pump is located so we turned off the water and the pump. When we turn on the water pump, it runs and stops and runs and stops. We’re DESPERATE for suggestions.

[flybouy]

First question, did you bleed tha air from the water lines? First turn the valves on the water heater from winter bypass to normal. Then turn on the water pump and open all hot and cold faucets inside and out. After eack faucet runs without spitting air for a few mins. turn all faucets off and listen for pump. If it starts to run again then you have a water leak.

[wrvond]

Scale build up on the diaphragm and valves will cause low flow and leak back - occasional pump cycling with no faucets open or tank filling up when hooked up to city water.
Your unit is pretty new, so I rather doubt scaling due to a lack of sanitation is the culprit, but it's entirely possible there is construction debris inside the pump keeping the valve assembly or check valve from seating.

[CDRVing]

We found a local guy that was able to figure out what was wrong with a long phone conversation and a few pics through text. Our pump died, apparently the pump has a check valve and when the pump stopped working, the water flowed from the City water connection through the pump to the fresh water tank. We were told to disconnect the outlet side of the pump and he gave us a plug to screw into that outside for $1. It worked! We are so thankful to Shenny’s RV Service Company for excellent advice and an easy fix that saved the weekend.

[1tenor]

I just replaced the check valve mine for the same reason. It's a pretty simple an inexpensive fix. As suggested by others here, I put a filter in line on the intake side of the pump to keep the problem from recurring.