Flush King vs. RV Hydroflush
When you dump your black tank, you want to make sure it’s completely clean. One way to accomplish this is to use a flushing valve; this is an attachment for the end of your sewer outlet, which allows you to blast water up into the tank. This can also help clean the sensors, and remove any debris caught on the sewer gate valve, causing it to leak and drip.
Two popular brands of flushing valves are the Flush King and the Hydroflush. Both have a clear plastic barrel, so you can see when the flush water runs clean. Both also have a built-in back-flow preventer to keep the dirty water from flowing back into your water hose. However, never use your freshwater hose with a flushing valve. Even though the back-flow preventer is supposed to prevent dirty water from flowing back into the hose, it’s best to keep a separate hose for this dirty job.
However, while both of these products are similar, there are some key differences.
The Hydroflush has a 45-degree bend, allowing you to not only rinse out your waste tanks but also flush out your sewer hose. If your drain line to the black tank is straight and short the Hydroflush will do a good job. But if it’s longer or has any bends it may not work well.
The Flush King
The big difference with the Flush King is it also has a gate valve at the back end; when the Flush King gate valve is closed and the black tank gate valve is open, it forces the water back up into the tank. This gate valve is also useful if your black tank gate valve is leaky. However, it adds an additional length that may not fit on some RVs. You’ll need room to pull the handle on the Flush King gate valve, and if your motorhome has a low clearance, the additional gate valve will make it even lower. The addition of the gate valve also makes the FlushKING, on average, twice as expensive as the Hydroflush.
Problems with Both the Hydroflush and the Flush King
One issue you may encounter with either of these products is, if your sewer drainage lines have any bends, or if the lines are very long, the flush water simply won’t reach into the tank. Unless the water can shoot straight up into the tank, all you will accomplish is rinsing off the gate valves for the gray and back tanks.
Buying either of these products can be very useful, as long as the water will shoot straight up into the tank. At the very least, using a flushing valve will help keep the gate valves on your RV clean.