It may depend on the refrigerator you have. I access the hose to the ice maker through the access panel on the outside of our MH. The 1/4 inch line runs into a solenoid valve and I disconnect the top and bottom hoses to let the water drain. Generally the 1/4 inch line runs into the coach to a filter. I our case it is under the sink in the kitchen. If so your may have a shut off valve on that line.
I do all my own stunts
03 Dolphin LX 6355, Workhorse W22, 8.1 vortec, 04 CR-V, Blue Ox, Brake Pro----Norm, Barb and
Doc(He's a PhD)