First, I don't have this setup so I can't be 100% sure... but I think I can make some pretty good educated guesses.
Im the picture I've numbered the valves. (ignore the two verticle lines, they were scribble accidents I didn't catch until I posted)
Valve 1: shuts off the cold water supply to it all.
Valve 2: shuts off cold water into the water heater.
Valve 3: Shuts off hot water leaving the water heater.
Valve 4: Water heater bypass valve.
Valve 5: Water heater drain.
Why all the valves...
Winterization of the water heater.
Winterization:
You don't want RV antifreeze in the water tank so.
1) Turn off water heater (will burn out if you miss this)
2) Drain Tank: Close Valve 1, Open Valve 5. May need to open the over pressure relief valve to let air in (reclose it when done)
3) Bypass tank: Close Valves 2, 3, 5, open valves 1 and 4.
4) you can now pump RV antifreeze into all the plumbing, hot and cold, without it getting into the water heater.
De-Winterization
1) purge all the RV antifreeze out of the hot and cold plumbing.
2)Fill water heater: Close valve 4, open valves 2 and 3. (make sure the overpressure relief valve is closed too).
3) Open the hot water side of a faucet, let it run until water comes out without any air spurting/surging. Close the faucet.
4) Turn on hot water heater.
I may have Valves 1 and 5 flip flopped. Look under the RV, which ever has a pipe that just dumps onto the ground, that is the drain valve and the other is the supply. However, the one with blue sharpie all over it, valve 1, I suspect is the water supply.
Linear Mode
