Steve, we also have the sealand and they're a great unit. After I flush, lift the pedal to add a bit more water to the bowl, that's the way ours works. At first I didn't know how to add water after flushing, then I finally read the instructions. Hope you get your problem fixed ok.
Best regards, Jim
Jim & SherrySeward
2000 Residency 3790 v10 w/tags 5 Star tune & Banks system Suzuki XL7 toad