Exact same problem here!
Ours is a 2019, same model and exactly the same problem. Our check valve was defective. Thor authorized replacement. After replaced, we notice water flooding out from below our coach under the outdoor kitchen when we’d use the sink. As per usual with our Camping World, take the coach to fix one issue and drive away with two additional! They did not hook the plumbing pipes back together!!!!!!! 🤦🏼*♀️
Finally, now, all is well!!
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