Chateau 28A Black Tank Drain Issue Solved

[TheWags]

I just wanted to pass on some info for anyone purchasing a 28A and possibly other models. We are new to the RV lifestyle and we were having an issue with draining the black water tank. Nothing seemed to come out. We learned the hard way that there is an additional drain valve located underneath the coach towards the back on the passenger side that must also be open for the tank to drain from the main sewer valves on the driver side. Essentially two valves have to be opened for the tank to drain. I had searched videos and forums for help, found nothing, and eventually had to call Thor to ask for help.
Again, just wanted to pass on this info for anyone that might eventually have the same problem.
Happy travels everyone!
The Wags

[16ACE27]

Originally Posted by TheWags

I just wanted to pass on some info for anyone purchasing a 28A and possibly other models. We are new to the RV lifestyle and we were having an issue with draining the black water tank. Nothing seemed to come out. We learned the hard way that there is an additional drain valve located underneath the coach towards the back on the passenger side that must also be open for the tank to drain from the main sewer valves on the driver side. Essentially two valves have to be opened for the tank to drain. I had searched videos and forums for help, found nothing, and eventually had to call Thor to ask for help.
Again, just wanted to pass on this info for anyone that might eventually have the same problem.
Happy travels everyone!
The Wags

Thanks for refreshing what is a pretty common question/answer on this forum.

[LizB]

Thanks for this. I found it after we figured it out ourselves, you know, after I knew what search terms to use Still, I wish it were common knowledge.

[Chateau_Nomad]

2020 Thor Chateau 24F has the same black tank drain setup. And I am guilty of not knowing it was designed that way when purchased new. But I appreciate the extra measure of "safety" ...provided you close BOTH of them!

[Redsand]

I can appreciate your situation as well. In our case we bought the rig used with empty tanks or so the inside gages indicated. Nothing in the user manuals about a dual valve setup. Glad you shared once again and I share your experience with finding the correct search terms. I found our blank tank completely full from the previous owner. EU
The gage seems to function normally after the first dump and clean out.

[Judge]

Many of the Thor E-Series Class C's are plumbed this way... for future reference for others.

[Pete'sMH]

Just remember that there is a reason for having two valves. It keeps the, umm, solids from settling in the low point (the drain line under the coach) and causing an unappealing clog. Use them both!!

[Redsand]

The dual system works well and also protection from road hazards and rupture so a good design. Again it just surprised me that Thor or Four Winds at the time completely left out the extra hidden valve documentation. No mention anywhere.

[Sullyd59]

Make sure you close both .