Black tank building pressure

[billydan91]

I’ve noticed when I’m flushing my black tank it builds up pressure. I empty the tank then close the valve and add water with the flush. I usually go inside after a few minutes to check the level. I turned the water off and I went inside to check the level and I heard air or water escaping. I opened the toiled to check and boom, water all over. Isn’t the vent supposed to prevent that from happening ? I know some people say to leave the valve open while flushing but I want to make sure everything comes out of the tank so I fill it a few times to make sure it’s clean. Anyone know what’s going on ?

[nomad297]

Originally Posted by billydan91

I’ve noticed when I’m flushing my black tank it builds up pressure. I empty the tank then close the valve and add water with the flush. I usually go inside after a few minutes to check the level. I turned the water off and I went inside to check the level and I heard air or water escaping. I opened the toiled to check and boom, water all over. Isn’t the vent supposed to prevent that from happening ? I know some people say to leave the valve open while flushing but I want to make sure everything comes out of the tank so I fill it a few times to make sure it’s clean. Anyone know what’s going on ?

If you filled your tank too much and the level went higher than your toilet seal, it will do exactly what you described. The vent has nothing to do with it.

Bruce

[billydan91]

Originally Posted by nomad297

If you filled your tank too much and the level went higher than your toilet seal, it will do exactly what you described. The vent has nothing to do with it.

Bruce

I never fill it more than 1/3. Also when I look down the toilet I see water but it’s just under the seal. Even when the tank is empty. It never seems to be empty. Is there a pipe that angles down into the tank or does it go straight down to the tank.