Water leaking under an RV: locate the source

For water leaking under an RV, stop the suspected water source when safe and record the location, timing and operating equipment. Keep people away from possible wastewater and wet electrical equipment. Color and odor alone cannot prove which system is leaking.

Reduce the release before tracing it

If a fresh-water leak is suspected, turn off the pump and close the external water source through safe access. Turn off affected heater energy according to its instructions. Do not keep filling a tank to make a hidden leak easier to find.

Timing helps locate a leak without identifying it by color
When the drip appearsWhat to record
Pump or city supply is enabledValve state and nearby plumbing
Water heater heatsExact discharge point and heater model
Sink, shower or toilet is usedFixture and drain path
AC operates in humid weatherWhether water remains outside or enters the coach
After rain or snowmeltRoof/sidewall path and interior moisture

Do not dismiss heater discharge

The Dometic WH-series manual explains thermal expansion and warns against plugging the relief outlet. It requires cool stored water for its air-pocket procedure. That does not make a loose drain plug, tank leak or continual relief discharge acceptable.

The Suburban tank-water-heater guide uses a different tank/anode arrangement on covered models. Match the actual heater before selecting a seal, plug or anode. Never tighten or remove a hot, pressurized fitting as a first check.

Record a leak without extending the damageStop the suspected water source through safe controlsThen: Keep clear of wastewater and wet electrical equipmentThen: Arrange source repair and inspection of concealed moistureRecord a leak without extending the damageStop the suspected water source through safe controlsKeep clear of wastewater and wet electrical equipmentArrange source repair and inspection of concealed moisture

Wastewater requires containment and safe disposal

Stop using the affected fixture if a wastewater leak is suspected. Keep children and pets clear and arrange appropriate repair and cleanup. Do not release tank contents onto a campsite or assume clear-looking liquid is uncontaminated.

A valve outlet, hose connection, tank fitting and cracked tank need different repairs. A cap catching drips does not repair the underlying valve. Avoid removing an underbelly or entering beneath an unsupported vehicle to investigate.

Drying starts after the source is controlled

Water can travel before it becomes visible beneath the RV. Record interior dampness, wet insulation and affected compartments for the repair provider. A dry surface later does not establish that the structure behind it is dry.

Condensate outside an operating AC can be expected, but water entering the ceiling needs investigation. See AC water and cooling symptoms or roof/ceiling leaks. Use pump checks for pressure loss without a located drip.