KnowMyRigIf your residential refrigerator isn't making ice, or you’re standing in the kitchen trying to trace lines for winterization, you already know the main frustration: you turned the obvious valve under the kitchen sink, the ice maker metal wire arm is down, and... absolutely nothing is happening.
Alliance designs these rigs with multiple fail-safes (and occasional factory-assembly quirks) that mean turning on one valve is rarely enough. To completely manage the water supply to your 310RL ice maker, you actually need to check a total of three separate locations.
Here is the exact layout of the 2026 310RL water delivery system for the fridge.
The 3-Step Valve & Line Checklist
1. The Primary Island Shut-Off
The first place everyone looks is under the kitchen island sink.
The Location: Open the cabinet doors beneath the sink. You will see the main hot and cold PEX lines. Branching off the cold line is a dedicated, small inline shut-off valve.
The Action: Ensure this is turned parallel to the water line (Open). If you’ve done this and still have zero water flow, leave it on and move to step two.
2. The Hidden Under-Cabinet Valve
Because the refrigerator is located on the kitchen slide-out, Alliance plumbs a secondary inline valve inside the cabinetry itself to safeguard against slide-movement leaks.
The Location: Look at the cabinetry space situated between your refrigerator and the stove. Open the lower cabinet door/drawer. Inside, under the shelf, you will find a false wood panel held in place by a few factory screws.
The Action: Back those screws out and remove the panel. Behind it, you will find a hidden section of the water line and a second inline valve. From the factory (or after a dealer winterization), this valve is almost always left closed. Flip this valve open.
3. The Exterior Under-Slide Valve
Because the water line has to transition from the main body of the 5th wheel into the moving slide-out, there is a physical transition point under the rig.
The Location: Walk outside the rig, go under the kitchen slide-out, and look up toward the middle underside of the slide mechanism.
The Action: Look for an exposed PEX water line loop. Right near the transition point, there is an exterior shut-off valve. Squat down and look directly upward under the underbelly area to spot it. Ensure this valve is also clear and open.
A Note on Winterizing
When the end of the season hits, remembering this triple-valve setup is critical. If you choose to blow out your lines with compressed air or pump RV antifreeze (the "pink stuff") through the system, leaving any of these three valves closed will trap stagnant water in that specific segment of PEX, leading to a split line beneath your slide or island the following spring.
If you prefer to completely avoid running antifreeze through your refrigerator's internal water matrix, closing the under-sink island valve early allows you to isolate and drain the rest of the rig while keeping the appliance line dry.