Studer Valve failing ???

[Ford truck guy]

While camping this past weekend, I had a small issue... my drains in the bathroom all worked perfectly, that is until I closed the grey valves the night before leaving to allow the grey water to accumulate for dumping..

When the valves were closed, during a shower, the water was draining fine, then it backed up for a few seconds.... I heard a "BURP" and it all went done and was fine again...

Once I got out of the shower I saw water spots ALL OVER the sink and mirror.. It burped UP from the bathroom sink...

Could the Studer valve cause this?? Again, all was fine for a week with the grey valves OPEN... It happened twice, both was when the valves were just closed

[drj564]

I’m not 100% sure how your vents are plumbed but the vents on the roof should relieve pressure in the tanks unless they are clogged. The vents under your vanity sinks and island should only vent so the sink drains. In other words, they should only let air in, not out.

Were the tanks full or close to full when this happened?

[XCMARK]

you will need to take the wall down in the basement but I would guess the vent that goes to the roof is either not connected or the vent is all the way to the bottom of the tank and air cant get in or out of the tank. The vents under the sink are to let are into the tank not out, they are one way valves so as you drain the tanks they flow freely.

Maybe if its never done this before you have a bees next in the vent stack going to the roof???? You could pull the roof vent covers and put a garden hose down them and see if the water come out of the tank drain OR maybe it clears the nest.

[Ford truck guy]

Thanks, I thought that... Once I get the Redwood back to my house, i will rip into the basement and look at the vent.....