New owner of a 2021 Montana High Country

[Djenn102096]

Hi everyone,

We just purchased a 2021 High Country and it's on a seasonal site in Wells, ME with a full hook-up to town water and sewer. The last RV I owned was more than 15 years ago and obviously the improvements and technology has dramatically changed!

My question is regarding the black and grey water tanks. I was instructed to open the blackwater termination valve to drain the tank when the indicator reads at least 2/3rds full and then open the grey water termination valve to flush the drain pipe. Is it recommended to perform a tank flush at that time? The RV has an inlet to attach a hose connected to a fresh water supply. See the photo of the water supply inlet and tank termination valves.

Montana waste water connections_terminations.pdf

There is an inlet below the city water connection to attach an external hose from a fresh water supply. Would I leave the black water termination valve open when flushing the tank or would another method be recommended?

Thanks for any help!

Dave

[Gonefishing]

When I flush my tank I leave the valve open and flush for at least 30 minutes

[Daryles]

Don't forget you have two grey tank dump valves. The one in your picture dumps the bathroom (sink/shower) grey tank. There should be one near the driver's side right front wheel in the wheel well area. This one dumps the kitchen (galley) grey tank.
Make a P trap with your sewer hose to prevent bad odors coming up.

[jimcol]

Well you can't go by the tank indicator because they are never accurate. We always listen for the burp when flushing the stool to tell us the black tank is getting full. You'll know it when you hear it. We never used the black tank flush until the end of our trip and was heading home to put the 5'er in storage. I know the book says never use the back flush unless the drain valve is open. Problem with that is it never really cleans the entire tank. I would dump the tank, close the drain valve, turn the water on to the black tank flush, stand right there and listen to the tank filling. (Do not get distracted as you will forget and either overfill and/or rupture your black tank. You can hear the spray going into the tank. Once the sprayer is under water, the sound will tell you, I dump the tank. If everything looks clean exiting the tank, visible via the clear elbow I place between the discharge pipe and the sewer hose, I call it good. If not I close the dump valve and repeat.
I see more people wasting a ton of water trying to get their tanks perfectly clean after each dump. That's only important to me when I'm getting ready to place the unit in storage to avoid waste drying out on the sides of the tank or creating residual odors.

[Djenn102096]

Originally Posted by Daryles

Don't forget you have two grey tank dump valves. The one in your picture dumps the bathroom (sink/shower) grey tank. There should be one near the driver's side right front wheel in the wheel well area. This one dumps the kitchen (galley) grey tank.
Make a P trap with your sewer hose to prevent bad odors coming up.

Hi Daryl - thanks for the tip. Yes, there is another grey tank - I spoke with the person who sold the camper to me and he said he always left the galley open? Our camper also has a washing machine which uses a lot of water and can fill the other grey tank quickly.

[Djenn102096]

Originally Posted by jimcol

Well you can't go by the tank indicator because they are never accurate. We always listen for the burp when flushing the stool to tell us the black tank is getting full. You'll know it when you hear it. We never used the black tank flush until the end of our trip and was heading home to put the 5'er in storage. I know the book says never use the back flush unless the drain valve is open. Problem with that is it never really cleans the entire tank. I would dump the tank, close the drain valve, turn the water on to the black tank flush, stand right there and listen to the tank filling. (Do not get distracted as you will forget and either overfill and/or rupture your black tank. You can hear the spray going into the tank. Once the sprayer is under water, the sound will tell you, I dump the tank. If everything looks clean exiting the tank, visible via the clear elbow I place between the discharge pipe and the sewer hose, I call it good. If not I close the dump valve and repeat.
I see more people wasting a ton of water trying to get their tanks perfectly clean after each dump. That's only important to me when I'm getting ready to place the unit in storage to avoid waste drying out on the sides of the tank or creating residual odors.

Hi Jim - thanks for the tips. I agree that the indicator isn't accurate because I emptied the black water tank and could hear it draining through the white pvc discharge pipe and lasted for several minutes. I followed that up by opening the grey water discharge as recommended in the manual. The indicator light still showed the black water tank as 2/3rds full!

Problem I have in flushing the black tank is I have no way to tell if the water is clear since it discharges into a town sewer through what looks like 4-inch diameter pvc drain pipe. Would it make sense to drain the back tank, leave the valve open and flush the tank with town water connecting the supply hose to the white intake in the photo?

Thanks for any advice you can offer!

[Foldbak]

Whenever I dump I flush 4 times. I just use a 5 minute timer. Even though a 1/2 pipe will supply around 36 GPM, the sprayer reduces the volume substantially. Then I add 3 toilet bowls of fresh water and 2 pods.