Gray Tank 2 Drains Slowly

[PappaJohn]

We have had our 2021 310GK for a couple of months and Gray Tank 2 has always drained slowly. It does eventually fully empty.

I expect that the issue is some sort of blockage in the tank vent or the drain line. It doesn’t seem to be getting better or worse.

Any thoughts?

John

[ThePowells]

PappaJohn There have been reports of the plastic disc that is drilled out for the vent and line installations falling into the tank then migrating to the drain when dumping, but my feeble thought is that the plastic should float until the tank is almost empty and then may block it a little bit. My first thought is that the blade valve isn't opening completely. Your handle should move about 1 1/2 inches total. Another question would be is the tank vent clear? Do you hear any blurbles when you pull the handle indicating that it is venting thru the drain. Do you have a clear elbow where you can see the flow and is it pretty solid and steady or is it in need of Flowmax.

[flyfshrockies]

PappaJohn We have a 2021 Imagine 2600RB and the front grey tank burbles at first then drains slow at the end. I believe that the vent does not work well and the long run from the front to the rear has a slight upward bend about 5 feet from where it exits the underbelly. It flows well once started and eventually empties. IMHO the tanks are long and only 6 or7 inches high to fit in the area, when getting close to empty there is very little head pressure and thus all of the tanks on our unit suffer from the slow drain at the end. It helps to elevate the front of the unit some to improve the flow. I decided that unless the situation gets worse I will live with it.

Dave

[PappaJohn]

Jerry and Dave thanks for the responses. The gate valve handle moves about the right amount and I do have a clear elbow where it can watch the water. Normally the elbow fills up with water when the valve is opened but with this tank it starts out with a flow that fills maybe 1/10 the volume of the elbow. I don’t hear any gurgling of air trying to get back into the tank.

i think the idea of a piece of plastic or something blocking the drain makes the most sense. I guess I will also live with it unless it gets worse.

[Jlawles2]

PappaJohn Remember that the grey tank drain is not the same diameter as the black tank drain valve. Most grey tank valves are 2" (IIRC you can look in the parts section to confirm). Because of the major difference in diameters the grey tanks do drain slower and is noticeable in the clear elbow.

[PappaJohn]

Thanks for the input. Gray 1 drains like normal but #2 is like a snail.

[Cate&Rob]

PappaJohn
Hi John,

Gate valves come in two sizes. 3" and 1.5". Grey tanks can have either and we have one of each on our Reflection. A 3" on the shower tank and a 1.5" on the galley tank. You can tell which size you have by how far the pull handle moves. If it is the same as the black tank it is a 3" valve. Half of that and it is a 1.5" valve. I would expect a Solitude to have all 3" gate valves . . . but, I don't know this for sure.

Draining our galley grey through the 1.5" gate valve still fills half the clear elbow . . . so, I think you have some type of blockage. The hole saw disc from installing the fill or vent pipe is a distinct possibility.

Unfortunately, the only way to solve this is to disassemble the drain system to find and remove the blockage. Something you probably should get done while you are within the warranty period.

Rob

[PappaJohn]

Good comment about how far the dump valve handles move. I think all three of mine move about the same amount but I will check next time I dump.

John

[Jkwilson]

One thing to try is to have the air admittance valve for that tank ready to remove for dumping and see if it dumps faster with it off.

Another thing is to buy an endoscope camera for your phone or tablet. I use mine often, and several times for the RV. Easy to take a look at the valve and inside of the tank. Generally you can get one for about $40. Mine even lets me see my brake pads without disassembling the hub.

[BobinICT]

One thing to try is to have the air admittance valve for that tank ready to remove for dumping and see if it dumps faster with it off.

Another thing is to buy an endoscope camera for your phone or tablet. I use mine often, and several times for the RV. Easy to take a look at the valve and inside of the tank. Generally you can get one for about $40. Mine even lets me see my brake pads without disassembling the hub.

We have the same issue with gray #2, drains real slow in the end after a decent flow to start off. What it the "air admittance valve"? Our gray tank vent is on the side a little above the kitchen sink. Thanks in advance.

[Jkwilson]

We have the same issue with gray #2, drains real slow in the end after a decent flow to start off. What it the "air admittance valve"? Our gray tank vent is on the side a little above the kitchen sink. Thanks in advance.

The air admittance valve is the plumbing vent for the sink. Most rigs have one under the kitchen sink and one under the bathroom sink. Some Imagines are plumbed a little differently in the kitchen.

[Yoda]

One other place to check is the roof vent. Wasps love to build nests in them here. I documented finding this in my solar install. Lucky I did not get stung.