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Old 05-30-2016, 04:42 AM   #1
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Black tank flush problem

The flushing system on our 2010 RK3000 has stopped accepting water. I inspected the one way check valve that's conveniently located in the wall behind the shower, it's ok. So, I think the sprayer in the tank is blocked. Has anyone ever cleared one successfully? or should I just bite the bullet and drop the tank.

Thanks in advance for any help.
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Old 05-30-2016, 04:47 AM   #2
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You are probably right, but I don't think there is anyway to check that little worthless valve short of removing it. Many of us took them out, in my case while the rig was still under warranty, and use an external backflow preventer.
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Old 05-30-2016, 06:27 AM   #3
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I think there is room on the front of the tank to remove the offending rinse head and clean or replace. At least that is the case on my unit. John
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Old 05-30-2016, 10:56 AM   #4
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I had it happen once. I put about two cups of powdered laundry detergent (pre-dissolved in water), and a cup of bleach down the toilet, and filled the black tank through the toilet until I could see the water level up to the open toilet ball valve. Let it set that way for about a week, then drained the tank, and the sprayer has worked fine ever since.
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Old 05-30-2016, 12:04 PM   #5
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At least once a year I fill the black tank about 1/3 full and put a cup of dish-washing machine detergent before leaving on at least a trip when we'll be stopping at a full hookup CG. Drain it all out after hooking up, add toilet chem & water, and use. This has worked fine for me.
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Old 05-30-2016, 01:29 PM   #6
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Don't drop the tank. Several external back flush connectors available from Amazon or any rev parts source, using a hose to back flush. Connect between the hose and the tank outlet and work great, better in my opinion than the OEM flush.

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Old 10-22-2017, 09:14 PM   #7
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Black Tank flush

Question - the black tank flush only has a spray head into the tank and not a separate spray at the valve, correct?

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Old 10-22-2017, 11:26 PM   #8
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The spray head is located at the opposite end of the black tank from where the drain valve is located. This is where ours is located:
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Old 10-23-2017, 07:48 AM   #9
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If I was you I would open up the area to all the plumbing in the basement and find the 2 pipes that go to that valve and cut them off them use sharkbite fittings to connect them together thus eliminating the valve.

Next get a blow out fitting that screws into the flush port and try to add compressed air to dislodge the debris in the spray head. I would not put more that 40-50 psi in. See if you can get some water in ahead of the air to flush it out.
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