Malfunctioning grey tank valve

[viking1]

Just picked up a 2021 AS FB23 last week and am currently on the road having a problem with grey water tank valve. Black water valve works perfect but when we open the grey water valve completely only a small amount flows out. It takes two hours to drain the tank leaving it wide open. Where should I look for this issue?

[LAWBC]

Are you sure you are opening the valve all the way? It usually should be 31/2 inches to open fully. if not then take some Silicone spray and shoot it at the valve rod moving it slowly back and forth it may just be hung up.
If that dose not change things then.

Take a hose at the entrance to the the grey valve and open it and back- flush it, there might be some debris hanging up at the exit.
If that dose not work then check your vent stack opening on the roof (you might need to remove the cover and poke a light down. ( I suspect that should not be your problem).

Good hunting

[viking1]

Originally Posted by LAWBC

Are you sure you are opening the valve all the way? It usually should be 31/2 inches to open fully. if not then take some Silicone spray and shoot it at the valve rod moving it slowly back and forth it may just be hung up.
If that dose not change things then.

Take a hose at the entrance to the the grey valve and open it and back- flush it, there might be some debris hanging up at the exit.
If that dose not work then check your vent stack opening on the roof (you might need to remove the cover and poke a light down. ( I suspect that should not be your problem).

Good hunting

Thanks. We did open the valve all the way and even poked a stick up inside as far as it will go.

[pcskier]

Originally Posted by viking1

Thanks. We did open the valve all the way and even poked a stick up inside as far as it will go.

As mentioned, try sticking a hose up the main waste pipe and try to 'catch it' where the grey drain pipe intersects and then flush it. Mine was trickling recently and it turns out there was a lot of debris (coffee grounds in my case) that had built up and blocked the opening. If that doesn't work try a short flexible snake that you can wiggle up into the grey tank drain pipe.

[BayouBiker]

The Parts book has illustrations of the drain valve and piping layout which may help in getting the hose in the right direction for the grey tank. It shows the grey valve in and to the left the small pipe entering on the 90 ell of the larger pipe the valve is ver close. Run the water hose up the pipe till you hit the restriction. Probably construction trash...... hope it comes out.

[viking1]

A sloppy pipe connection may be the reason for slow draining because the sliding valve seems to be opening and closing correctly. Maybe some kind of Mickey Mouse patch for a poor alignment?

[djb75]

We had a similar problem with the black water tank on our Class C. It turned out that when they used a hole saw to cut out the opening for the pipe. When they did this, the disk fell into the tank, and subsequently covered most of the drain hole. One possibility might be to move the trailer forward a little and brake sharply (trying to move the disk over a little). If you get improved flow (even for a little bit, until the disk drifts back over to the drain hole), this might be your problem.

[ROBERT CROSS]

I open the black tank, close the grey hook up a hose and back flush.

Bob
🇺🇸

[viking1]

Originally Posted by djb75

We had a similar problem with the black water tank on our Class C. It turned out that when they used a hole saw to cut out the opening for the pipe. When they did this, the disk fell into the tank, and subsequently covered most of the drain hole. One possibility might be to move the trailer forward a little and brake sharply (trying to move the disk over a little). If you get improved flow (even for a little bit, until the disk drifts back over to the drain hole), this might be your problem.

Now that I'm home I'll the snake line.

[viking1]

So I finally scored a repair date for warranty work on the grey tank valve and low-flowing furnace vents. Although my initial salesman in Texas told me via email that his techs insist that the grey water valve was intentionally designed this year to flow extremely slow for whatever reason, the local guys in Temecula found different. Seems like some kind of cap was loose in the grey water tank that was causing the blockage. They found it and pulled it out.
I have not tested the valve yet because I am still waiting on a solution for the low-flow furnace vent. No one seems to have an answer to that yet...ho hum