Some RVs have an interior control panel near the front dashboard you can use to deactivate the power supply. If you don’t have time to wait for the heater to cool, run hot water inside the RV. When the water comes out cool, then you can start draining the lines. If you’re unsure about the location of the heater controls, as well as the water tanks and valves, refer to your RV’s owner’s manual.
Some RVs also have low drain point valves nearby. They will be close to the freshwater tank on the side or back end of the RV and labeled. Open them as well to help drain the lines. The valve can be in other spots, including inside the RV. It depends on the model you have. However, the freshwater always drains out from the bottom of the RV.
These tanks, along with their valves, can be positioned elsewhere depending on the RV. They are usually near the back end on the same side as the freshwater tank, but may be accessible through a separate exterior panel. Keep in mind that some older RV models may not have separate black and gray tanks. The tank drains may also be located underneath the RV.
Purchase an RV sewer kit to get all the parts you need to drain the tanks. Kits are available online and at RV centers. Note that the rules for dumping sewage may vary depending on where you live. Check with your local government for specifics. You can always go to a campground with a dumping point to drain your sewage tanks.
Always clear out the black water tank first so the gray water washes out any sewage left inside the water line. If you accidentally open the black water tank first, run water through the lines, such as by flushing the toilet a few times.
The pump switch is typically located next to the heater controls. Check around the kitchen and underneath sinks as well. You can run the pump for about 15 to 20 seconds to help drain water after opening the valves. However, make sure you shut it off after that so it doesn’t get damaged.
Have a 7⁄8 in (2. 2 cm) socket wrench to rotate the plug and pull it out. Some RVs require a 15⁄16 in (2. 4 cm) socket instead. Expect to see some white sediment come out of the heater. It’s ugly and looks like sand, but it’s normal. You can insert a hose into the drain to rinse out any sediment left inside the heater.
Some RVs have a built-in air compressor that you can use to blow out the lines. [8] X Research source Air compressors for car tires are too small for an RV. Also, oil tank compressors aren’t the best choice since they can blow debris into the water lines. If your air compressor uses a filter, replace the filter with a clean one to keep the RV’s lines nice and clean.
If the plug has a small cap on the end, remove it by turning it counterclockwise. Blowout plugs, or compression adapters, are available online and at most RV centers.
If your compressor has a blow gun, take advantage of it to make the process easier. Use a hose with open adapters on both sides so you can insert both the blowout plug and the tip of the blow gun. If you’re unable to hook up a hose, buy an adapter called a coupler to hook it to the blowout plug. Hoses are different, since they can have a plug-in “male” end or open “female” ends that male plugs fit into.
The battery is typically located in the front right or left side of a car’s engine bay. It looks like a small box with metal terminals labeled + and -. Clamp the compressor’s hookups onto these terminals. If your compressor runs on electricity, plug it into a nearby outlet. Use an extension cord as needed to connect to distant outlets.
If your compressor doesn’t have a regulator, buy a separate one and fit it on the end of the blowout plug. Attach the compressor hose to the other end. High air pressure can cause the water lines to burst, so set the compressor with caution. A low pressure setting is more than enough to clear out the lines.
This part is easier if you have someone helping you. Have them hold the compressor hose or tell you when water stops flowing from the faucet. If you’re using a compressor with a blow gun, try doing 2 separate blasts of air for 15 seconds each. It will be more than enough to clear the lines.
If your sink has separate controls for warm and cold water, make sure you clear both lines out separately. If the faucet has a single control for both warm and cold water, you can activate the warm water to clear both lines at once. However, treating them separately ensures they are 100% drained.
If you have a water filter, disconnect and empty it as well. For more assistance dealing with components like dishwashers and washing machines, check your owner’s manual. It will have recommendations for effectively clearing the lines.
Remember to also disconnect the sewer hose and garden hose if you haven’t already.
