[Leisure Time Larry]

No worries. I'm less familiar with the 5230 since I have a BT Cruiser 5211, but I think I can help. The systems on these are VERY basic. First, mine is plumbed so that there is only one valve to turn for NORMAL/BYPASS modes of the water heater. That is located just to the rear of the water heater on the inside of the coach. My guess is that you can access yours by removing the lower drawer under the rear closet by the main door. Pull out, lift slightly, pull more and lower the front and lifting the rear slide wheels out of the track. Even if it's not there, take some photos of what is under and back there for future reference. If it's not there, my second guess would be access from under the bathroom sink, to the left.

There is no bypass valve or antifreeze intake line standard on mine. Just a line from the freshwater tank to the water pump. My water pump is easily accessible, so I just made my own hose out of clear tubing with a proper fitting that screws onto the inlet side of the water pump. When I winterize, I just empty the freshwater tank, unscrew the line going into the pump, screw on my custom hose onto the pump, put the other end into a bottle of antifreeze then run the pump and turn on the faucets one-by-one to get antifreeze through the lines.

For de-winterizing, find the 3 gate valves in the system...1 is the freshwater tank drain. It is usually near the tank and pump which should be under your passenger side sofa. The pump and drain valve may be hidden under a plywood box under the sofa. 2 is the low-point drain for the COLD water lines and 3 is the low-point drain for the HOT water lines. The low point drains should be in the outside compartment just forward of the sewer valves. Just make sure all 3 are shut so that you can fill and pressurize your system properly.