View Full Version : Blank tank plumbing question

09-26-2021, 08:14 AM
Hi All!
I have a question about how the toilet is plumbed to the black tank in my 2020 Springdale SG280bh. I just replaced my toilet (Dometic 300) and when I removed the old one, I was expecting a straight pipe to the black tank and an odor. Instead, there was NO smell whatsoever and some standing water about a foot down from the toilet.

I *know* the tank was empty when we last went camping, although the meter shows half full.

So my question is there a p-trap between the toilet and the black tank or is it just a poop mountain that needs to be dealt with?

When I dump the tank, everything seems to flow out fine and I ALWAYS use the tank sprayer for several minutes until I don't see any more material coming out.


09-26-2021, 01:30 PM
There is no P trap. You could be seeing the bottom of the tank. I put about 5 gal in the tank after dumping. It’s not good to start with a dry tank as things will stick to the bottom

09-26-2021, 01:35 PM
Thanks, Marshall. That could be it. I also put ~5 gals in after I dump the tanks before heading home, hoping the agitation helps clean it out.


09-26-2021, 01:39 PM
Others say the sensors arenít worth a crap (pun intended), but very trailer I have owned and worked has worked when they are clean. You probably have toilet paper hung up, did the monitor panel say empty when you first bought the trailer?

09-27-2021, 01:16 PM
I haven't really looked at our new 220 pot, but same in our race trailer - opt sits directly over the black tank. I replaced the potty in the race trailer year before last because I didn't get all the water out of the flush valve. Oops. Had a spare pot in a box, so R&R was just quicker/easier. And same - after every use I spray the heck out of the black tank with one of those sprayer/whirligig things. The sensors work fine in that trailer even after 4 years of use. We use an additive, make sure we use septic friendly/easy dissolve paper and rinse-rinse-rinse. Will probably use a combo with the installed wash out on the road side of the RV and the wand.