Melt water needs a route out
Water in a DC box is usually melt from the evaporator plate that has not found its drain. On a boat or in a van that water reaches wiring and structure, so a small blocked drain is worth clearing promptly rather than mopping repeatedly.
What you are seeing
- Water pooling in the bottom of the box.
- Contents sitting in a shallow layer of water.
- Water appearing after a defrost or a warm day.
- Damp in the locker below the unit.
- Water at the base with ice still on the plate.
- Not this fault: A warm cabinet with water inside is a cooling fault first - read that page.
- Not this fault: Water elsewhere on a boat may be a deck or hull leak entirely.
Most likely causes, in Dometic order
- Drain blocked with debris or salt residue — Why ranked: First on this equipment. It is small, low and in a wet place, and it blocks routinely.
- Frost melting faster than the drain can clear it — Why ranked: Second: a warm day or a defrost releases a lot of water at once.
- Unit not sitting level in its locker, so water runs away from the drain — Why ranked: Third. On a boat at rest this is common, and the water collects in a corner with no drain.
- Seal leaking, so more moisture enters than the design allows — Why ranked: Fourth. More moisture in means more frost and more melt, and the drain is overwhelmed continuously.
- A container leaking inside the box — Why ranked: Last, and worth excluding early because it is nothing to do with the appliance.
What to check, in order
- Find the drain point in the base of the box and check it is clear. — Because: This is the leading cause and it is visible once the box is emptied.
- Note whether the water followed a defrost or a warm day. — Because: Timing tied to a thaw is the second cause and it clears once the drain is open.
- Check whether the unit sits level in its locker. — Because: A slope sends melt to a corner with no drain in it.
- Smell or taste the pooled liquid rather than assuming it is water. — Because: A leaking container is not an appliance fault at all.
Checks you can do safely
- Empty the box and mop out the pooled water. — N: 1 — Tools: Cloth, sponge — Time: moderate
- Isolate the unit and let any plate ice melt fully. — N: 2 — Tools: Towels — Time: moderate
- Clear the drain gently and flush it with fresh water. — N: 3 — Tools: Soft brush — Time: moderate
- Check the unit sits level in its locker and adjust if it can be. — N: 4 — Tools: Level — Time: moderate
- Check every container inside for a cracked lid or a weeping seal. — N: 5 — Tools: None — Time: quick
Before you open anything
Safety
Unplug the appliance or switch off its breaker before removing any panel. A capacitor can hold a charge after the power is off. Never clear a drain with a metal probe near an evaporator plate - the refrigerant circuit is inside it. Water in a boat or a van reaches DC wiring quickly, so isolate at the battery switch first. Let ice melt rather than chipping it. Never use a heat source inside the box. Dry the locker fully before restoring power.
When this becomes a service call
Water returns with a clear drain and the unit level. The drain cannot be cleared from inside the box. Damp is spreading into the locker or the structure. There is water at the base together with a loss of cooling.
Nearest pages
What this page does not cover
This page covers Dometic DC compressor refrigerators and cool boxes. It does not cover the absorption refrigerators sold under the same name, whose drains run out through the vent area, and it names no model-specific drain part. Where a family- or model-specific page exists it supersedes this one.
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
