When you look at the ultra heat website, you will see all of the available options for tank heaters and they also have sewer fitting heaters as well. I have not installed them yet, but my plan for the future, is to install the tank heaters and fitting heaters on my BC to prevent any possible issues in the future. We got down into the teens this winter and I have not had any freezing issues YET...but winter is not over. More snow is coming later this week!