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Old 06-16-2020, 09:51 PM   #1
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Join Date: May 2017
Location: Crowley, Texas
Posts: 117
Black Tank Maintenance

My wife and I own a large (37 ft) Class A motor home and the Black Tank has never registered empty. We bought the coach when it was four years old and had probably sat unused for an extended time.

The problem with the sensors not reading correctly is that the "master" toilet is a Thetford electronic toilet which will not flush if the black tank is registering Full.

About a month ago, after spending about $300 at a dealer trying to get the black tank emptied, I ran the black tank flush system multiple times with the water running clear when I emptied it. I then filled it again with clean water and added enzyme chemicals and it has been left standing for about a month. Is there any problem with leaving it filled with clean water and chemicals? Thanks.
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Old 06-16-2020, 10:43 PM   #2
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I don't see any problem with it.
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Old 06-22-2020, 11:50 PM   #3
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Location: Savannah
Posts: 763
We always add some Happy Camper and 5 gallons of water after we flush the black tank.
If we don't go anywhere it doesn't hurt the tank and the valve seals don't dry out.
We keep some water in the toilet and sink traps as well.
2017 Forester 3051S
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Old 06-23-2020, 12:36 AM   #4
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Location: Bow WA
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We always leave our black tank with a solution of Calgon water softener and dish soap.
Ram 2500 FR Surveyor 251rks
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Old 06-23-2020, 12:13 PM   #5
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Location: Crowley, Texas
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Yesterday, I put some “Tank Blaster” in the Black tank thru the half bath toilet. I’ll let it sit for awhile, then drive it to slosh the liquid around, then dump the tank to see what the level reads. Thanks for the inputs!
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black, black tank, maintenance, tank

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