Black Tank Flush Recommendations

[renderit]

Before I head out on each trip and once a week while out before hitting the road I mix two cups of Calgon and a couple of gallons of HOT water and dump in the sinks and then the same in the stool. Calgon is a water softener. It will coat the tank and seems to keep stuff from sticking to it VERY well. Nothing bad in it, it is just like soft water when you dump.

[moosetags]

Originally Posted by Airstream12557

I stay at a permanent spot all winter and leave my sewer hose connected, but I leave the gray and black valves closed. You DO NOT want to leave the black valve open all the time. Bad things WILL happen! See my earlier post on this thread on how I dump.

A very big ditto on this issue! Leaving the black tank valve open while camping will result in what is called "Black Hills Syndrome". This dreaded condition can result in having to replace the black tank.

Brian

[switz]

In our 2015 23D, we have the small 18 gallon black tank just like the 19, 20, & 23FB. We also have the small 21 gallon gray tank like the 19 & 20 models. We always use the built in tank flusher system.

If the tank is not full, I turn on the flusher system to add volume to the tank and get the percentage close to 90% full and open the valve. When the flow is slow, I close the valve (flush water still running) and nearly refill the tank and flush again. If items of interest come past the view "window", I flush again. When the all clear message is visually conveyed, I close the black valve and open the gray tank valve. When it is empty, I close the drain valve and open the black valve and get another clean water flush of the hose. I turn off the water and then close the black tank valve.

BTW. Use a back flow preventer at the trailer connection water inlet to prevent contamination of the hose even with a dedicated flush hose.

We then add three gallons of water with our TankTecks product that helps keep the tank clean during the sloshing when going down the road. I also put that product with three gallons of water into the gray tank.

In the Classic with much larger tanks, after dumping we put in five gallons plus the tankTech but use the same dumping procedure.

Do not park and open the black dump valve. The solids will not flow away like in the house and there will become a real issue inside the tank if the solids accumulate.

[cactusjk]

You are the first to mention Tanktechs. Any reason you settled on that product?

Originally Posted by switz

In our 2015 23D, we have the small 18 gallon black tank just like the 19, 20, & 23FB. We also have the small 21 gallon gray tank like the 19 & 20 models. We always use the built in tank flusher system.

If the tank is not full, I turn on the flusher system to add volume to the tank and get the percentage close to 90% full and open the valve. When the flow is slow, I close the valve (flush water still running) and nearly refill the tank and flush again. If items of interest come past the view "window", I flush again. When the all clear message is visually conveyed, I close the black valve and open the gray tank valve. When it is empty, I close the drain valve and open the black valve and get another clean water flush of the hose. I turn off the water and then close the black tank valve.

BTW. Use a back flow preventer at the trailer connection water inlet to prevent contamination of the hose even with a dedicated flush hose.

We then add three gallons of water with our TankTecks product that helps keep the tank clean during the sloshing when going down the road. I also put that product with three gallons of water into the gray tank.

In the Classic with much larger tanks, after dumping we put in five gallons plus the tankTech but use the same dumping procedure.

Do not park and open the black dump valve. The solids will not flow away like in the house and there will become a real issue inside the tank if the solids accumulate.

[gwilsonobx]

It's best to keep your black tank valve closed untill that tank is 3/4 full and then dump to the hookup.
Run the flush with dump valve closed untill. 1/2 to 3/4 full and dump again. Don't forget to add some water and chemical to that freshly cleaned tank.

[cactusjk]

Is there a trick to making sure that the clear Rhino 45 degree swivel elbows don't leak?

[m.hony]

Tighten the locking collar?


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[OTRA15]

We also have a 2014 FC and the plastic vacuum breaker also leaked on us. Have not been able to get to a dealer to have it replaced. I would suggest confirming you have the new brass vacuum breaker as part of the black water back-flush system on your 2015, and you should be good to go.

Peter

Originally Posted by cactusjk

Is it best to use the OEM connection or go with something like a Rhino Blaster?

Also, how often should you do the flush?

Originally Posted by Cannonball

Our factory black tank flush leaked on our 2014 Sport. I thought it was a stupid device, so did not rush to get it repaired. I did eventually get it fixed (stupid cracked vacuum breaker), and now wish I had it repaired on Day One. I always fill the black tank prior to dumping, even if I have to just run in some water with the foot pedal. Dump, black tank flush on for 10-15 minutes, easy. We also have the clear elbow (wife hates it, thinks it is juvenile, maybe because I named it "The Turd Tunnel") and the water is usually flowing clear within the first couple of minutes. Easy.

[Cannonball]

Replace the gasket, or make sure the gasket is there?

[cactusjk]

Originally Posted by OTRA15

We also have a 2014 FC and the plastic vacuum breaker also leaked on us. Have not been able to get to a dealer to have it replaced. I would suggest confirming you have the new brass vacuum breaker as part of the black water back-flush system on your 2015, and you should be good to go.



Peter

Good feedback. Will check. Thanks.

[cactusjk]

2015 FC 23D has brass!

[OTRA15]

Originally Posted by cactusjk

2015 FC 23D has brass!

Excellent news, thanks for the feedback.

[Flathead1984]

This is a old thread, but the topic fits. We are newbies and today I emptied my black tank. It was about half full, but has sat for 6 weeks. Getting snarky. After draining black , and grey, I hooked up the hose to the flush inlet. It seemed like a lot of back pressure. Also, could not detect any additional flow.

Is there a check valve or something that I need to open?

[n2916s]

Are you sure you are hooked up to the flushing port and not the city water inlet? My SIL got those backward once — had a shiny $65K water fountain after awhile...