Topic: Kitchen Sink Waterless Trap blocks. What’s the reason. (Read 2388 times) previous topic - next topic

2017 Unity TB. Rather than a traditional P-Trap, the kitchen sink has a waterless trap to prevent sewer gasses from backing up into the coach. The waterless trap is in-line, and consists of a rubber diaphragm that is normally closed, but opens under pressure when draining the kitchen sink, then collapses to close again when the sink has been drained empty.

Our waterless trap has become “blocked” three or four times in the past 18 months, seemingly at random. This necessitates disassembly and re-opening manually the rubber diaphragm.

Anyone else have similar problems?  Any idea as to the cause, or how to prevent?

I think they use the HepVO-type traps when a P-trap won't fit in the space.

We've only had our shower one act up, and were able to "burp" it with a cupped hand over the drain.  Out of curiosity, did yours stop up after a period of non-use?  That's when our shower did.  I suspect the rubber dried and stuck. 

Our kitchen sink decided yesterday not drain normally, was very slow then all of a sudden it drained.  I guess the valve decided to open.
We have been living in it for the last 7 weeks, so not dry.  Will keep an eye out.