Check your RV P-traps by: Coleen, the RVing editor
It could be there is no water in one of the P-traps.
The way drains work, the P-traps are configured so that they hold water. That water acts as a barrier so gasses from the holding tanks don?t come back into the trailer. With the water gone, the barrier is gone.
When you turn on the water and some goes down the drain, it displaces gasses in the holding tank. Normally, they should go out the vents. However, if you have a dry P-trap, the gasses could be coming up the drain and into the rig.
As to how or why the P-traps would dry out, if you haven't used them for a couple of weeks or so, it could have evaporated. Or, it could have sloshed out when going around turns or driving up and down hills.
