- does the hot water tank need to be drained and where is the drain valve?
Yes, it does. The drain valve is the off white hex head nylon plug toards the bottom and slightly to left of center in your outside picture. When draining, be sure to pull the P&T relieve valve, this is towards the top of the unit, it is a round fitting with a “loose” lever on a cam you lift up to open the valve.
- where is the bypass valve?
Cannot find in your interior pictures. Close off the cold inlet to the tank, not the hot output. My preference is to drain the hot water tank, rock the unit a bit to make sure it is as empty as possible, and then close off the tank when introducing the antifreeze into the system.
- do I leave antifreeze in the grey and black water tanks?
Yes! Pour almost all of 5 gallons of RV antifreeze into the fresh water system (Before you do make sure fresh, grey and black are EMPTY), turn pump on, open all faucets (don’t forget the shower outside and refrigerator ice maker if you have them) and run them until they are the color of the antifreeze. Fill and flush the toilet twice or three times.
You should now have RV antifreeze in your fresh, grey & black tanks, all lines and traps in the sinks. (I even open the grey tank drain briefly just to get antifreeze in the discharge tube)
This topic only touches on the water system of your RV
. I can’t stress enough looking for additional resources on everything you should be doing, as a for instance:
- Battery removal
- Remove all perishables
- lubrication of all exposed parts (jacks, hitch, chains, etc)
- keeping the fridge open/fresh
- shutting off gas
- inflating tires, etc.
- I put flea collars in my outer compartments, ant traps inside, cedar blocks in drawers, closets, etc.
- There is much to do!
My wife and I did this and it took about 2 hours to do everything, plan on 4 for the first time!