Fresh Water drain for my Ventana LE

You might want to get a water softener if you frequent hard water areas. I recently got one and really like it Water Softener

Thanks for the advise. I feel better knowing that the task is so easily corrected.

Most coaches have a drain for the hot water tank as well. I'm guessing that you would not want to leave any bad water in there either.
I do not have a Newmar but with my Monaco coach I actually have three drains that will completely drain all water out of my coach. One is before, and another one is after, the water pump and then there is a separate drain for the water heater.
Be sure that if you drain the water heater, that you shut off power and/or gas to it first.

Yes, it is the lowest point in the system and will drain your tank and water lines which is what you want to get all the hard water out. Fill with softer water and run through the pump and all faucets and then drain again.

at the water compartment. There is a low point valve, is that it ??

Where do you think it is, lets start there.