Gray Tank

[Thehillguy]

I was thinking the capacity of my gray tank(2020 30FW) wasn't holding what it should so I emptied it completely. Gauge read empty. I poured 5 gallons down the shower drain, the gauge showed 1/3 full. Another 5, 2/3 full. Next 5, same reading. 2-3 gallons more & it stopped taking water. Very slowly I was able to finish the fourth 5 gallon bucket but no more. So a total of 20 gallons, half of what it should hold. Thoughts? TIA

[bclemens]

When you say "stopped taking water", you mean it back filled into the shower? Or the gauge showed full?

There are two possibilities in theory.

1. The vent stack is too far into the tank and the water level is capping...happens, but rarely.
2. You are not level. If you look at the drain schematic, specifically page two, you can see that the shower enters in on the shallow side of the tank. If the coach is leaning to the passenger side at all, the water could be collecting there and capping the vent regardless of how far the vent is in.

See if you can get it to lean to the driver side act all and if that helps.

If you are referring to just the gauges (which it doesn't sound like), then it could be location of the sensors.

[Thehillguy]

Thanks for your quick reply... The coach is level & it happens at other times as well. At 20 gallons, the gauge showed full and water backed up in the shower. It did very slowly go down the drain some.

[bclemens]

Might be one we need to get a dealer to take a look at. Could be the vent pushed past the rubber boot ledge that is supposed to stop it.

[Thehillguy]

Again, thanks for your help with this. When I look at the plumbing routing drawings you attached, I can see that the vent through the roof has a T where the black tank vent comes in. Seems that would prevent just pulling up the vent stack. When I first discovered this issue, I asked CJ Superczynski his thoughts. He said the techs suggesting sending me some tank supports and someone needs to reseat the vent in the correct position. Since that sounded 'involved', that's when I posted to the Dynamax Owner's forum to see if others have encountered similar issues. Would the fix involve pulling off wall panels to access the tank boot & vent pipe? Does the suggestion of the tank supports indicate the tanks may need additional support to stay in place? Additionally, the black tank level starts at 1/3 when empty & shows full soon after using.
Looking forward to happy camping!

[bclemens]

Originally Posted by Thehillguy

Again, thanks for your help with this. When I look at the plumbing routing drawings you attached, I can see that the vent through the roof has a T where the black tank vent comes in. Seems that would prevent just pulling up the vent stack. When I first discovered this issue, I asked CJ Superczynski his thoughts. He said the techs suggesting sending me some tank supports and someone needs to reseat the vent in the correct position. Since that sounded 'involved', that's when I posted to the Dynamax Owner's forum to see if others have encountered similar issues. Would the fix involve pulling off wall panels to access the tank boot & vent pipe? Does the suggestion of the tank supports indicate the tanks may need additional support to stay in place? Additionally, the black tank level starts at 1/3 when empty & shows full soon after using.
Looking forward to happy camping!

That could just be a sensor location issue. They are stuck on...and if they come off who knows where they get put back on...and an irregular tank makes the location difficult as well...if they are even spaced on the "low side" of the tank...that will fill quickly before the longer shallow section will fill.

[bratbros]

I had a similar issue last fall when I was at a primitive site. I know Brian said to try and lean the coach to the driver side and see if it helps, but what I did was lean the coach to the passenger side. I had everything underneath the shower apart fixing different tank issue last summer and noticed there wasn't much fall from the shower drain to the grey tank. My theory is that if it's leaning to the driver side the water won't run into the tank...probably not your issue but you might try it and see.

Disclaimer: Mine is the first 30FW built and the plumbing is a little different than the schematic Brian posted.

[Wfieldin]

Anyone found a good reason this is happening, I did a 5 gallon bucket test on my grey tank and shower starts to back up at around 14 gallons?