Problem with toilet spraying water on wall when flushing

Hello everyone,

I am trying to fix a problem we have developed in the new to us 2008 Teton 5th wheel trailer.

We have the Dometic Concerto 4410 electric flush toilet with optional sprayer. When we flush the toilet there is water spraying from the rear of the toilet onto the back wall of the bathroom. Also when we try to use the optional sprayer there is no water that comes out of the sprayer. I have been looking thru the owner's manual and come to conclude that I may need to replace the vacuum breaker. Does that sound like a reasonable solution to the problem?

But when I try to find the correct part to order I can't tell if I am looking at the correct item....seems they keep changing the parts numbers??? I tried calling Dometic but they route my call to a parts warehouse who says tell them the part I want and they will ship it. But I don't know the correct part to tell them???

I was also trying to find a you tube video to help show how to change out the part.

Any help would be appreciated.

Thanks,
Phil