[Daryles]

Interesting...
Cold water did NOT work but hot water DID work.
The source for BOTH is the freshwater tank via the water pump when you are disconnected from City Water.
No cold water faucet anywhere in the rig worked?

The problem I have with this "four season" camper is all the "air gaps".
Look under your frame. There are lots of holes and gaps. This allows cold (or hot, summer time) air into your underbelly and can freeze your pipes.
I used gorilla tape to close off all small openings (hydraulic lines, slide cylinder).
Use aluminum sheeting and cut to fit around the hydraulic jacks. Leave the opening around the propane tanks. They must have ventilation.
Take down your basement walls, crawl in and close the doors. You will see daylight coming in through all the gaps along the frame.
Look behind your basement wall aft of the convenience center towards your middle jack. Very large opening where the jack comes through. To close this you will need sheet aluminum cut to fit.
Some have sprayed styrofoam on the inside of the J channel skirt to insulate the frame.
There is a panel under the bottom shelf in the pantry. Behind the panel is the water heater. Again you can see daylight coming in around the edges. This requires fire retardant insulation around the water heater to block out the air gaps.
Under your kitchen island there is a panel covering your plumbing. Take it out and there is a big Triangle gap in the corner. Cut and fit styrofoam to fill the gap tight. Use gorilla tape to seal it in place.
Under the bathroom sink you will also find air gaps where the plumbing goes through the floor.
Remove the drawers closest to the fridge. At the back where the propane and electric wiring come through to the oven, there is a gap in the wall by the fridge. Remember the back of the fridge is vented to the outside. Cold air comes in through this gap. Mine is an RV fridge so I have to be careful because on the other side of that wall is the chimney for the fridge heater. I have to use flame retardant insulation here.
Look up in your hitch pin box, you will see your bedroom closet floor and a hole where your 7 way cable goes through the frame. I taped up the hole and wedged 2" styrofoam board up against the floor.
Look at the inside door frame of the pantry. You will see a gap. This leads to the basement.
Make sure your inside and outside slide seals are good.
Look at bottom corners of your windows, you will see 1/4" inch gap for condensation weep hole. Nothing you can do about that unless you want to tape plastic sheets over the windows. If you do, use heavy gauge clear vinyl on the outside. Use metal foil air conditioner tape to secure it to the outside of your rig. Then put either large bubble wrap on the inside of the glass (allows sunlight in) or use clear vinyl again. Having two sealed air voids will help prevent condensation.