When the gray tank is full

Deb55

Is it normal for the kitchen sink to leak underneath when the gray tank is full? I (luckily) had a bowl stored under the sink, and when I took it out to use it, it was full of water. Last night, our gray tank reached capacity and wouldn't drain the sink until we emptied the tank. Is this leaking a problem for the dealer to check? 

dragonsdofly

@Deb55, yes it is normal for the sink not to drain when the gray tank is full, the other option is that the sink drains but the shower pan backs up. However, a leak in the plumbing under the sink is a leak. The probable reason for noticing is the full gray tank with water sitting in the sink. Because the water was there for a prolonged time, any tiny pinhole or loose coupler began to leak. The leak is not related to a full gray tank. If the plumbing was sealed, it would not have leaked. Period. The plumbing issue may be solved by simply hand tightening the PVC joints, although may have to advance to something else. Anyone with decent plumbing knowledge can look and/or diagnose and probably repair without a full blown trip to the dealer for service. If it's a more advanced repair, then I'd schedule a service appt. As it is, unless you have standing water in that section of the plumbing, you may not ever see it leak again. Whatever you choose to do, good luck. -Denise 

ScottG

Assuming we are talking about an S model here, it seems odd to me that gray water wouldn't be backing up into the shower pan long before it would reach the trap under the sink.

Deb55

ScottG said:

Assuming we are talking about an S model here, it seems odd to me that gray water wouldn't be backing up into the shower pan long before it would reach the trap under the sink.

No, sorry--we have a 2018 T@B 400. I should've made that clear! 

ScottG

I'm less familiar with the specifics of the 400, but I would still expect the shower drain to be lower than the sink trap.

On models without a bathroom, then I could see gray water backing up as far as the sink.

BigGrover

Yes, it would back up in the shower first.  The leak is not secondary to the gray tank being full.  It is a plumbing leak that needs to be fixed

Verna

I have had the sink back up and I have had the shower to back up in my 400. I think it depends on whether you are spot on level or now.....that’s the only thing I could figure out. 

If your black tank isn’t full, you could drain some gray water from the sewer outlet and dump it in the toilet. The black tank is 12 gallons.