That is so weird. How old are your chickens? Are they normally this nervous? You might have to manually dip their beaks so they know it's water, but wait for someone else to chime in. I don't want to traumatize them.
My chickens will be apprehensive about new things, but that normally wears off in a couple hours. For them to be avoiding food and water for a week seems excessive.
One idea is to remove the water from the waterer, dry it out, then put their food in the reservoir. THAT is their only food for the day, and lock them in with it until they eat. Obviously provide their usual water on the side. Hopefully that will knock them out of it, then you can convert it back as their waterer.