Graywater

Graywater in an RV refers to the waste water that comes from sinks and showers. It’s not as dirty as blackwater (which is from the toilet), but it’s not clean either. Graywater gets its name because it often looks gray due to the detergents and soap in it.

When the graywater tank in an RV is full, you’ll usually get a warning from an LED indicator. If this warning is ignored, a more noticeable sign is when water starts backing up from the lowest drain, often the shower. This is especially important for RVers who have washing machines, as these appliances use a lot of water. It’s crucial to ensure the sewer hose is connected and the graywater valve is open before using the washer, otherwise, the water will overflow.

Graywater also plays a key role in RV maintenance. When emptying tanks, RVers typically empty the blackwater tank first and then the graywater. The soapy water from the graywater helps clean out the sewer hose. However, many campers keep their graywater tank open when connected to a sewer pipe. So, it’s important to monitor the blackwater level. As it nears full, you should close the graywater valve to save some water to flush the sewer hose after emptying the blackwater. If this isn’t done, you might need to run extra water down the sink to collect enough graywater for a good hose flush.

In older RVs that don’t have a built-in gray water tank, RVers might need to install an aftermarket tank, connect a hose for full service, or use a 5-gallon bucket to manage graywater.