Thanks O-B. I dumped the grey water on the ground, but I can't dump the black tank, and there's just a small amount in it - maybe a few gallons of very old water. Can I just dump some antifreeze in it? Should I use different antifreeze since it isn't potable water?
How do you get the antifreeze into the water lines? The fresh water tank is set so that it retains several gallons of water no matter what you do. The drain plug on it is an inch or more above the bottom of the tank (idiotic design). Do you pour X-number of gallons into the remaining fresh water, then pump it through? Do I have to disconnect the line from the fresh tank? It used to have a leak where it connected at the tank, and I believe the repairman glued it in order to stop it. Finally, I've been in that water compartment hundreds of times, and fixed leaks on the back of the water tank, but I've never seen a valve for the water heater. There's a valve to bypass the water pump, but none for the heater as far as I can tell. Is there another way to deal with it? If it's any help, it's a 1987 Fleetwood Bounded.
Thanks for your help.