Dumping Tanks and Flushing Blackwater

[Sormand]

We are new owners of the Oakmont 400FL. We love our units but have questions on dumping the tanks. Yesterday was the front time at the dump station after a 6 days stay at the lake. All tanks were showing full. I hooked up the hose and pulled the valves 1 at a time as told by the dealer. I waited until I could not hear anything running through the hose. We got back to our spot and hooked everything up and the black tank should 1/3 full. Not sure if I didn't do something right. They did not tell me about flushing the black water system. I did find a water inlet area by the external water hook up and tank fill that says something about flushing. I have no idea how to hook up to that to flush the black water tank. Can someone explain the best way to do this? Thanks so much.

Steve and Missy

 

[danemayer]

Hi Sormand,

Congratulations on your new Oakmont and welcome to the Heartland Owners Forum.

We have an owner written Water Systems Guide that will explain all of this and provide some additional tips. Some of the other guides may be helpful to you as well. You can get to them by selecting the TOOLS tab at top of page, and then selecting HUG - Heartland User Guides.

One thing you'll find very helpful is a clear twist-on sewer adapter so you can see exactly what's happening when you dump the tanks. Here's one from Amazon. Something else you'll come to appreciate is a twist-on gate valve like this. The external gate valve stays on all the time and is closed during travel. When you hook up to the sewer, attach the hose first, then open the external valve. Any fluid/waste in the pipes will stay there until your hose is attached, instead of pouring out on your shoes.

Btw, the tank indicators inside are notoriously unreliable. A little wet TP hanging on the sensor will give you a false reading for a long, long time.

 

[murry135]

Welcome to HOC and good luck with you new Oakmont. You did everything right so far but I would like to add that you need to hook a fresh water hose to the FLUSH for the Black tank when dumping. This is an internal sprinkler system that helps clean out the sludge and solids within the black tank. There are numerous procedures out there to help clean all your tanks and keep them operating the best. I recommend looking on the internet, looking in the "TOOLS" section here on the forum and talking to others to find what options are there and you want to use. Good Luck and enjoy!

 

[TravelTiger]

Welcome to HOC and good luck with you new Oakmont. You did everything right so far but I would like to add that you need to hook a fresh water hose to the FLUSH for the Black tank when dumping. This is an internal sprinkler system that helps clean out the sludge and solids within the black tank. There are numerous procedures out there to help clean all your tanks and keep them operating the best. I recommend looking on the internet, looking in the "TOOLS" section here on the forum and talking to others to find what options are there and you want to use. Good Luck and enjoy!

Slight correction, do NOT use your drinking water hose for flushing, best to buy a regular garden hose to use exclusively for this. You do not want to potentially contaminate your fresh water hose with sewage.

 

[Nbomar]

I'm just curious how it would contaminate the hose? Water doesn't back flow through the system as far as I know. If it was hooked to the same water source you use for the tank fill, I don't see the harm. I've just never heard this before.


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[Nabo]

We set up this weird contraction. The black lever knobs are set right now for fresh water but when it's time to flush/back wash the lines, I first close the fresh water line. First - pull the tank valve to dumb whats in the tank, then open the back wash line to start back washing. Once I hear the back flush/sprayer water start to come thru the sewer hose, I close the black tank valve for 10-12 minutes (use a stop watch app on my cell phone). Once the timer has gone off, open the tank to dumb/flush the tank. Once the dumping has slowed down (hearing water noise thru the hose), I close the tank valve again and back wash for another 12 minutes again using the stop watch. Most of the time this method pretty well cleans the tank and the lights shows empty but every now and then the 1/3 light will show. Must have a little piece of trash that didn't wash out which happens.

 

[danemayer]

We set up this weird contraction. The black lever knobs are set right now for fresh water but when it's time to flush/back wash the lines, I first close the fresh water line. First - pull the tank valve to dumb whats in the tank, then open the back wash line to start back washing. Once I hear the back flush/sprayer water start to come thru the sewer hose, I close the black tank valve for 10-12 minutes (use a stop watch app on my cell phone). Once the timer has gone off, open the tank to dumb/flush the tank. Once the dumping has slowed down (hearing water noise thru the hose), I close the tank valve again and back wash for another 12 minutes again using the stop watch. Most of the time this method pretty well cleans the tank and the lights shows empty but every now and then the 1/3 light will show. Must have a little piece of trash that didn't wash out which happens.

Nathan,

12 minutes is a long time depending on water flow rate. If you were getting 4 gallons/minute, which is certainly possible, that would put 48 gallons into your black tank. Since the black tank holds 45 gallons, that could be a problem. At 5 gallons/minute, you'd probably have black water coming out the roof.

I follow a similar procedure, but time it to around 6 minutes. If I have poor water flow, I might go to 7 minutes. And yes, using a timer is critical.

 

[Nabo]

Dan - we have a pressure valve on the cg water tap set at 40 psi which has never overflowed the tank. 12 minutes doesn't even fill the tank by the lights on the control panel.

 

[danemayer]

Dan - we have a pressure valve on the cg water tap set at 40 psi which has never overflowed. 12 minutes doesn't even fill the tank by the lights on the control panel.

Water pressure and water flow are different. You can be at 40 psi and have 5 gpm. But it sounds like either your pressure regulator is also restricting water flow (which many do), or places you stay don't have good water flow.

 

[Nabo]

Yes it restricts the pressure - that's why we have it. On our 2006 Sundance - we didn't have a gauge on the water line and blow some pex lines in the camper. That's why we have the gauge set to restrict the incoming water and haven't had any problems since then on any of your other 4 campers.

Sormand - just a suggestion. Have someone inside the camper watching the tank lights to see how long it takes to get the full light button to show full. This will help you know how long to back wash your tanks.

 

[TxCowboy]

We set up this weird contraction. The black lever knobs are set right now for fresh water but when it's time to flush/back wash the lines, I first close the fresh water line. First - pull the tank valve to dumb whats in the tank, then open the back wash line to start back washing. Once I hear the back flush/sprayer water start to come thru the sewer hose, I close the black tank valve for 10-12 minutes (use a stop watch app on my cell phone). Once the timer has gone off, open the tank to dumb/flush the tank. Once the dumping has slowed down (hearing water noise thru the hose), I close the tank valve again and back wash for another 12 minutes again using the stop watch. Most of the time this method pretty well cleans the tank and the lights shows empty but every now and then the 1/3 light will show. Must have a little piece of trash that didn't wash out which happens.

We use the very same procedure but have to agree with Dan's comment above (#7). I personally fill the black tank for only about seven minutes but I do flush it at least twice.

My black tank sensor still only drops to about 2/3 even when I know the tank is totally empty but nobody in their right mind trusts those suckers anyway. LOL

EDIT: Nathan, one more thought on your contraption -- isn't that putting a LOT of weight on those plastic hose fittings??

 

[GOTTOYS]

I'm just curious how it would contaminate the hose? Water doesn't back flow through the system as far as I know. If it was hooked to the same water source you use for the tank fill, I don't see the harm. I've just never heard this before.


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I agree. I always dump my tank first then back flush it. I use the same hose. Have for years. I do have a backflow preventor valve at my flush connection. If you use a different hose...at some point it's hooked up to the same water faucet anyway...Hasn't killed me or made me sick yet..Don

 

[TravelTiger]

I'm just curious how it would contaminate the hose? Water doesn't back flow through the system as far as I know. If it was hooked to the same water source you use for the tank fill, I don't see the harm. I've just never heard this before.


Sent from my iPhone using Tapatalk

Yes it should not backflow. But as we've read on this forum, "stuff happens".

Have always used different hoses for flushing and drinking. It's what we were told "way back when."

 

[Nabo]

This contraption hasn't caused any problems on our last 3 units (08 Big Country, '12 Big Country and now our '15 Landmark). We lived in our last Big Country for over 2 years and haven't had the first leak.