Grey Tank not draining

I think you need to sort out the issue of whether you have two grey tank drain valves first of all.

How long have you owned this trailer?

A couple of things (that has previously been mentioned) comes to mind for me.

First, the pull handle stem has come loose from the gate assembly inside so the gate it NOT opening at all.

Second, there is another gate valve someplace for this particular tank that you're not aware of.

Gray tanks just don't plug up as there are nothing in them that is large enough to block the drain opening. So, in my opinion, one of the two items above has to be your problem.

Good luck...

Ron

You keep referencing, "both handles pulled black tank drains and 1 grey tank drains", some with 2 grey tanks have 2 grey tank drain valves if that's the case with yours you will have 3 valves to pull to dump all 3 tanks.

beemerphile1 wrote:

rhagfo wrote:

beemerphile1 wrote:
Use this with a hose to blow water up the drain line and dislodge the blockage.

These unfortunately do really blast that far up the pipe, My galley drain has about 15' of pipe before the valve. Best bet as it is Grey/galley, run a garden hose up the pipe to see if you can blast it out.

Assume you meant don't and not "do".

If you put a cap on the end, the water has nowhere to go but up the drain line.

Correct, thanks for the catch They Do Not blast very far up the pipe.

rhagfo wrote:

beemerphile1 wrote:
Use this with a hose to blow water up the drain line and dislodge the blockage.

These unfortunately do really blast that far up the pipe, My galley drain has about 15' of pipe before the valve. Best bet as it is Grey/galley, run a garden hose up the pipe to see if you can blast it out.

Assume you meant don't and not "do".

If you put a cap on the end, the water has nowhere to go but up the drain line.

beemerphile1 wrote:
Use this with a hose to blow water up the drain line and dislodge the blockage.

These unfortunately do really blast that far up the pipe, My galley drain has about 15' of pipe before the valve. Best bet as it is Grey/galley, run a garden hose up the pipe to see if you can blast it out.

Go Dogs wrote:

...Drano is a no-no in a plastic tank.

Not true. New homes are all built with plastic drain lines.

Although it could result in a mess, how about undoing a wire coat hanger and sending it up there to see what you poke into. At least it's not the black tank.

I think the shaft screws into the blade it may have unscrewed over time see if you can get it to screw into the blade. Or go to an RV store and look at a new blade assemble and see how there are put together you may have to replace yours.

Are you SURE the tank is full? Are you going by the 'full' level on the sensors? They often are inaccurate. Drano is a no-no in a plastic tank.