I don't know about the 2002 coach, but will proffer the configuration of our '06, Al. It's been mentioned here before by myself and others:
You said you can't see the waste tanks, but ours are easily found behind a hinged panel immediately forward of the curbside wheels. The door has no handle, but fastens underneath with two strap latches along its bottom edge. Many owners aren't aware of the access since it looks like a fixed body panel. Below is a photo I had on file of the view inside that bay, although it isn't as wide an angle to be as representative as it could be for your purposes.
Our coach has an aqua hot heat outlet in there along with its own thermosensor that turns it on around 40 degrees as I recall. It is relatively independent of the two heating zones in the living area. The water pump "cabinet" intrudes into the compartment via an adjacent wall so it is exposed to heating. The water tank is more forward in essentially the same bay as the HydroHot, and by sheer proximity to it stays above freezing.
-Joel
Addendum: a little curiosity led me to the following video tonight, and it confirms to me that your coach has the same access panel I referred to above that mine has, so check it out Al.
https://www.youtube.com/watch?v=OYCjdSAcEjA