Well the hot water tip has not worked for me today. I've tried it 3 times. Also, my blade has no buildup of minerals, etc, on top or bottom. Thetford said that once the blade has pulled back the seal edge it must be replaced. I am not looking forward to this removal due to the custom (poor) installation in my B. Have to drive up on blocks so I can crawl underneath & unbolt the unit. It really is a 2 person job as a wrench needs to be on the head of the bolt inside to prevent it turning while I'm underneath. I have jury rigged the wrench inside the last 2 times. Hope it works again. Sad.