New Owner Macerator Question

[Danneli]

I am still a newbie so have patience with me. I have a 2018 Midwest Weekend Sprinter. I have drained the black and gray tanks twice and both times I turn the open each tank turn on the macerator pump and within 10 minutes it gets to 1/3rd and then I wait for a half an hour and the light does not move off of the 1/3 full marking. I am sure there is a trick to this that I am not getting. Is there someone who knows the trick?

[rowiebowie]

Originally Posted by Danneli

I am still a newbie so have patience with me. I have a 2018 Midwest Weekend Sprinter. I have drained the black and gray tanks twice and both times I turn the open each tank turn on the macerator pump and within 10 minutes it gets to 1/3rd and then I wait for a half an hour and the light does not move off of the 1/3 full marking. I am sure there is a trick to this that I am not getting. Is there someone who knows the trick?

Welcome to the forum Danneli!

Not sure I understand your problem, but I hope you have not let your macerator pump run more than 3-4 minutes at a time (all it should take to empty your gray and black tanks). And I hope you never run it more than 10-15 seconds once thanks are emptied. The dumping fluid keeps the pump impeller lubricated and with out it, friction from heat can destroy the rubber impeller blades fairly easily.

Please tell me you haven't run your macerator pump for up to half an hour.
.

[rowiebowie]

Here is the link to the Thetford Sani-con Macerator instructions. I believe other brands operate the same general way.

https://www.thetford.com/wp-content/...021811_EFS.pdf

I'd also suggest you refer to any manuals and/or call Midwest customer support.
.

[Gryphon]

Tank sensors are notoriously unreliable. When emptying your tanks, the sound of the macerator pump will change when there is no more liquid passing through it. You need to listen for that & shut off the pump when it happens.

[Twinbridges]

Gryphon has it right. I have Midwest and you can hear the difference. And it is quick. Some folks don’t like the macerater but I sure like the ease with the retractable hose. Clean, fast and simple. No big hoses to mess with.

[engnrsrule]

Gryphon is right on the level indicators. In my Sprinter I can actually see the bottom of the black tank through the toilet, so can easily verify it is empty. To try and keep the sensors from being fouled I use tank treatments that are supposed to help (limited success). I also use a wand designed to jet out the black tank walls and top to remove all klingons. https://www.amazon.com/Valterra-A01-...dp/B000BGHYDO/

You should also never let the tanks be completely dry.

[Twinbridges]

The Midwest also has a built in tank spray to clean the black tank. You attach a hose and it has built in jet nozzles to clean the tanks of residual stuff. I use it once in a while but always before winterising.

[Danneli]

Originally Posted by engnrsrule

Gryphon is right on the level indicators. In my Sprinter I can actually see the bottom of the black tank through the toilet, so can easily verify it is empty. To try and keep the sensors from being fouled I use tank treatments that are supposed to help (limited success). I also use a wand designed to jet out the black tank walls and top to remove all klingons. https://www.amazon.com/Valterra-A01-...dp/B000BGHYDO/

You should also never let the tanks be completely dry.

Much thanks... just bought the master blaster.

[Roadtreker357]

It is rare that the black tank level indicator light goes to zero. I replaced the macerator one time and also replaced the macerator inlet piping and blade valve. In both instances I wanted to make sure the black tank was empty. This worked for me.
At the last campground before going home, completely dump the tank and then fill it half full of water and add some dish detergent.
Drive home so the sloshing around will do some cleaning and help break up remaining solids.
Dump at home (I have a dedicated dump pipe) and check the level indicator.
Completely fill the black tank through the toilet using a garden hose.
Dump again and check the level indicator.
It takes several refilling and dumping iterations to get rid of all brown colored water and to get the level indicator to show empty.

Otherwise, just use the macerator to dump, and stop the macerator when the noise changes and the hose dances around. Then pretty much don't worry about the level indicator reading empty. You will learn over time how long you can go before dumping is needed, regardless of the level indication.

[Bertiboo]

I’d like to install a short clear section of tube right at the macerator output to see when it is done. I tend to lift the outlet end a tiny bit (but still pointing into the drain) to see when it’s done. But not always that easy to tell from the sound (on mine)

[rowiebowie]

Originally Posted by Bertiboo

I’d like to install a short clear section of tube right at the macerator output to see when it is done. I tend to lift the outlet end a tiny bit (but still pointing into the drain) to see when it’s done. But not always that easy to tell from the sound (on mine)

It can be done. Thetford sells a macerator (Thetford 70224) that is designed as adetachable unit and has a gray water bypass. To convert to the bypass, they added a short section of 1" clear tubing between the pump outlet and the hose.

https://www.thetford.com/product/sanicon-system/

Scroll down to their twist-off model. Hard to find one for sale, however.

I bought this unit and have it permanently attached via the twist-on collar.