I have a 2008 big country 5th wheel bunk house. 3490 bhs. My sink keeps clogging continuously. We empty the tanks completely and water keeps coming up both sides. What can be wrong ??
As mentioned, your p-trap is probably clogged. Instead of using harsh chemicals that can cause some problems in some cases, recommend using a home combination of 1/2 cup baking soda and 1/2 cup of white vinegar. Let it sit for 20 or 30 min and flush with hot water.
You can always resort to chemicals if this doesn’t work. If you’re sure the trap is clear but sink still doesn’t drain, move to the next scenario that was suggested.
Yes it is the vent. Now how do we clean it?
I have read this thread. It begs the question, if you need to ask how large your tank is, when is the last time you dumped it? It is behaving like no air behind water, or the tank is full.