Black tank flushes only one tank?

[Mandersoon]

Hi all - I've got a Mountaineer 345DBQ, which has an inlet for flushing the black water tank(s). Insofar as I can tell, this inlet only flushes the one tank whose dump valve control is in the main control center/wet bay. The black tank with the control valve at the rear of the coach doesn't seem to get flushed this way. Just wanted to check if I am missing something.

[ChuckS]

Hopefullly it is plumbed to black tank. Open black tank valve and with flush hose hooks up turn water on and see if water flows fom black tank. Can’t imagine being hooked up to gray tanks.

[notanlines]

You would need two inlets to flush two tanks. One 5/8 hose will not carry enough water to properly flush two tanks with average pressure.

[Dave W]

Unless you have two toilets, you only need one black tank. If you have a second toilet you should have a second black tank which then should have its own flusher. Gray water tanks will never (seldom?) have a flusher though a kitchen sink tank might be a good candidate for one.

[Mandersoon]

Originally Posted by Dave W

Unless you have two toilets, you only need one black tank. If you have a second toilet you should have a second black tank which then should have its own flusher. Gray water tanks will never (seldom?) have a flusher though a kitchen sink tank might be a good candidate for one.

Yes, there are two toilets. The aft bathroom sink is plumbed to the rear black tank. I'm guessing that running the water in the sink for 10 minutes is the solution to flushing the tank.

[Dave W]

If you feel you need a built in flusher, CAMCO makes a 'Tornado' but reviews are only mediocre at best.

If you have a separate sewer drain hook up for that rear tank, both Camco and Valterra make a backflush fitting with a gate valve that does a good job. I have both and prefer the Valterra or even better, the back flusher on the macerator. Any of the three do a better job then the built in flusher.

I run water backwards into the black tank after a drain for 4-5 minutes two or three times, draining well after each back fill and usually the dump water is completely clear.

[Signguy71]

On my Fuzion 427 I have two toilets and two black water tanks and the flush does both black tanks. It does a great job on both tanks.

[mtofell]

My 308bhds is the same way. Front bathroom with toilet and sink only has the flush. Rear bathroom with toilet, sink, tub/shower doesn't have it. The front bathroom sink and toilet empty to the same tank with a valve up front. The kitchen sink and rear tub/shower go to gray, rear bathroom toilet and outside kitchen sink go to black tank. I've wondered about the flush thing as well. I'm not sure why they only put it on the one bathroom. I've had flush feature on other RVs and rarely use it. Filling the tank and letting it sit for a week or so seems to do the same thing or better.

[infantryofficer81]

Our Fuzion 420 functions the same way as Signguy71's unit. I'm not sure how it's plumed, but it'll pump water to both tanks.

[Auggie Waterman]

Our 2018 308 BHDS has two separate flush input hookups. One does the master bath/toilet and the other the main bath.