Winterizing black tank using outside shower line

I have a better way, IN fact 2 of 'em

First the OEM flush device on my RV was SELF WINTERIZING. Yup there is a Vacuum breaker mounted ABOVE the tank somewhere in the RV. with no pressure in the line this allows water to drain eitehr
Inlet to breaker, , back out the inlet

Breaker to Black tank.. into the tank.

At this point you are winterized, no need to do anything. PERIOD, and it worked just fine the first year that way

Next method. Compressed air.. Blow the water into the black tank. Then dump.

FInal method (THe one I use now and by far the best) I go south for the winter.

MMMMM guess I missed that line. Will have to remember that this winter

I have a hand pump that connects to the anti-freeze bottle. It takes about 20 cents worth of anti-freeze to flush the black tank rinser. It's cheap piece of mind when the temps go down to -20.

How much water can that line hold really? I know... a little bit of water freezing in the right place and you have a leak. I just blow mine out with air and have never had an issue. I keep the air pressure to 40psi max though.

I just blow it out with air (pressure regulated to about 50psi)
Takes 5 seconds and there's nothing to freeze.

I winterize my black tank flush using the outside shower connection every year. Works great.

siggyd777 wrote:
I just DUMP the black tank , close the valve & put a 1/2 gal. of
RV antifreeze down into the toilet. Never had a problem in cold
Chicagoland. I do the same for the gray tank by putting antifreeze
in every sink / shower trap.
Siggy

he's not talking about winterizing the black tank. he is winterizing the black tank sprayer.
bumpy

I just DUMP the black tank , close the valve & put a 1/2 gal. of
RV antifreeze down into the toilet. Never had a problem in cold
Chicagoland. I do the same for the gray tank by putting antifreeze
in every sink / shower trap.
Siggy

use a hand pump that fits the antifreeze bottle connect it your flush line and pump it by hand until you get some antifreeze out of your black tank drain valve

If you are concerned about the black tank flush line, put antifreeze into a hose, then connect to an outside faucet and put the contents of the hose into the line.