2020 Outlaw kitchen sink drains very slow

[Handy]

We just bought this new Outlaw and while inspecting it at the dealer I noticed that the kitchen sink drained very slow and the p-trap is installed right up against the bottom of the sink such that the water level sits at the strainer in the bottom of the sink. When I say slow, I mean that a quart of water takes about 20 seconds to drain when it should take about 5 seconds. The mechanic didn't think it was a big deal and I figured that I could fix it so I let it slide. At first, I thought there was not enough drop to the p-trap and I would just lower the p-trap (I am a general contractor). Unfortunately, there is not enough room to lower the p-trap. I removed the AAV and inspected it. The AAV is not defective (I also tried a new AAV just to make sure), and without the AAV installed the drain flows as it should. This tells me that water in the drain is developing pressure in the drain line instead of a vacuum which is preventing the AAV from opening. I am assuming that this may be happening because there is no vent on the grey water tank itself. However, I tested the sink drain with the grey water tank drain valve open and it was still slow draining. I would think this relieved any pressure but maybe not for some reason? The tank is very oddly shaped with a large flat section that stretches over under the kitchen sink. I confirmed that there are no blockages between the sink and the top of the grey water tank. Most people would say that I should just take it in for the dealer to fix under warranty, but I fix things for a living and I generally don't trust other people to fix things for me unless it is my last resort. By the way, we went on our first camping trip and everything else is working good, except for the low ground clearance, so I have a 6" lift kit ordered.

[GVP-The Boxcar Children]

That does sound odd. Our Aria 4000's kitchen sinks (twin) don't even have P-traps, and fell off on our last trip-both the coupling screw caps broke off. I suspect it broke because it was so rigidly installed that it had no capability to flex when rolling down the road.



Good luck-let us know what you find out.
GVP

[Bob Denman]

Could it be that the strainer is full of construction debris?

By the way: I'm glad to hear that your shakedown cruise was successful!

[safari]

Originally Posted by Handy

We just bought this new Outlaw and while inspecting it at the dealer I noticed that the kitchen sink drained very slow and the p-trap is installed right up against the bottom of the sink such that the water level sits at the strainer in the bottom of the sink. When I say slow, I mean that a quart of water takes about 20 seconds to drain when it should take about 5 seconds. The mechanic didn't think it was a big deal and I figured that I could fix it so I let it slide. At first, I thought there was not enough drop to the p-trap and I would just lower the p-trap (I am a general contractor). Unfortunately, there is not enough room to lower the p-trap. I removed the AAV and inspected it. The AAV is not defective (I also tried a new AAV just to make sure), and without the AAV installed the drain flows as it should. This tells me that water in the drain is developing pressure in the drain line instead of a vacuum which is preventing the AAV from opening. I am assuming that this may be happening because there is no vent on the grey water tank itself. However, I tested the sink drain with the grey water tank drain valve open and it was still slow draining. I would think this relieved any pressure but maybe not for some reason? The tank is very oddly shaped with a large flat section that stretches over under the kitchen sink. I confirmed that there are no blockages between the sink and the top of the grey water tank. Most people would say that I should just take it in for the dealer to fix under warranty, but I fix things for a living and I generally don't trust other people to fix things for me unless it is my last resort. By the way, we went on our first camping trip and everything else is working good, except for the low ground clearance, so I have a 6" lift kit ordered.

Hello Handy, When you check for blockage was that also from the AAV down the pipe.

[Handy]

I removed the p-trap which was clean and inserted a 1/4" hose through the drain pipe and down to where it enters the holding tank below the drawers. I also inserted the hose from the AAV down to the same point and it appeared to be clear. Also considering that the drain speed is normal without the AAV indicates that the pipes are clear. There is only one 360 Vent on the roof so I will assume that the black and grey tank vents combine into this. The vent is on the opposite side of the motorhome from the kitchen sink. I looked at the grey tank configuration closer this morning and it is very custom! It is about a 3" deep pancake spreading about 4'x4' under the floor with a deeper collection area on the opposite side of the motorhome by the main drain. There is a little finger at the edge of the grey tank where the drain pipe from the kitchen sink enters it. The grey tank is secured to the bottom of the floor at this point to keep it high and then slopes downwards to the other side of the motorhome at the main drain. My thoughts are that all the other drains are working so the kitchen sink end of the grey holding tank must not be benefitting from the holding tank vent. On another note, while inspecting the grey holding tank I found a cluster of 8-10 hoses, conduit, and wires wedged between the holding tank and the top of the chassis on the low side of the tank where it is supposed to rest on the chassis. Over time, especially driving with a full grey tank, these will get pinched between the holding tank and the chassis so they will need to be pulled out of there. Maybe this will affect my venting issue when the tank is able to come down a little more and rest on the chassis. Also, the abs pipe coming out of the grey tank is sloped upwards before it turns down to the main drain so I might have to add a couple of rubber couplings to allow it to stope downwards properly. I also found a rubber fuel hose pulled tight against a sharp metal edge a few feet forward of the gas tank in the rear.

[javelin]

I would agree that when AAV is removed and there is no issue with water leaving the sink, that there is likely no blockage downstream into the grey tank; and probably the shared roof vent is open as well. So if the AAV valves are good, then there is simply not enough vacuum being created by water leaving the sink and flowing through the trap to open the AAV properly IMO. Not sure if that is because there is little or no tail stock height below the sink (per your description) and before the trap to help create more head pressure (more vaccum on the AAV as waater goes down)? So how do you create more vacuum in that column of sink water to activate the AAV.....you said you have no room for a longer tailstock pipe before the trap.....and I don’t know if all AAV’s operate at the same set vacuum levels either.......raise the sink? Interesting problem.

[safari]

Originally Posted by Handy

I removed the p-trap which was clean and inserted a 1/4" hose through the drain pipe and down to where it enters the holding tank below the drawers. I also inserted the hose from the AAV down to the same point and it appeared to be clear. Also considering that the drain speed is normal without the AAV indicates that the pipes are clear. There is only one 360 Vent on the roof so I will assume that the black and grey tank vents combine into this. The vent is on the opposite side of the motorhome from the kitchen sink. I looked at the grey tank configuration closer this morning and it is very custom! It is about a 3" deep pancake spreading about 4'x4' under the floor with a deeper collection area on the opposite side of the motorhome by the main drain. There is a little finger at the edge of the grey tank where the drain pipe from the kitchen sink enters it. The grey tank is secured to the bottom of the floor at this point to keep it high and then slopes downwards to the other side of the motorhome at the main drain. My thoughts are that all the other drains are working so the kitchen sink end of the grey holding tank must not be benefitting from the holding tank vent. On another note, while inspecting the grey holding tank I found a cluster of 8-10 hoses, conduit, and wires wedged between the holding tank and the top of the chassis on the low side of the tank where it is supposed to rest on the chassis. Over time, especially driving with a full grey tank, these will get pinched between the holding tank and the chassis so they will need to be pulled out of there. Maybe this will affect my venting issue when the tank is able to come down a little more and rest on the chassis. Also, the abs pipe coming out of the grey tank is sloped upwards before it turns down to the main drain so I might have to add a couple of rubber couplings to allow it to stope downwards properly. I also found a rubber fuel hose pulled tight against a sharp metal edge a few feet forward of the gas tank in the rear.

I will look at mine when I get a chance see if anything looks odd,Thanks for the fuel hose fyi.

[Bob Denman]

Could the vent up on the roof be blocked somehow?

[Handy]

Update on this slow drain. I rebuilt the p-trap and drain pipes to go around the drawers so I could lower the p-trap 3.5" which increases the height of the AAV valve and moves the water level down below the basket strainer. The drain is still slow but it is visually much better as the water level disappears into the tailpiece. I also tried tilting the motorhome to create more slope in the grey tank away from the outlet of the kitchen sink drain pipe and it had no effect. I am still uncertain of why this drain is so much slower than the shower drain. Coincidentally I received communications from the Thor concierge department stating that they want to contact me several times in the next year to see how the motorhome is doing and how the dealer is doing. They gave me contact info and encouraged me to contact them with anything at any time. I sent a detailed email describing my slow drain, pinched wires and fuel line under the grey tank, and outlet pipe from grey tank sloping up. I also included a drawing of the drain circuit. I was positive, provided facts, and simply asked if they could provide me with any information that might help me. It has been 4 days and I have received no reply from Thor. At this stage I am going to be happy with the progress I have made on the drain, continue working on the other issues myself, and not have any expectations of what Thor's concierge department might do for me.

[javelin]

Sorry to hear no fast drainage success as yet. The other way to look at it is probably that the real purpose of the AAV is not for sink drainage, but rather to prevent the sink P trap water from being siphoned off when other water devices/drains are being used in the coach. So maybe the odd shape of the grey tank is a contributing factor (for easier blockages) and I am wondering if just using a small diameter flex hose as a snake is adequate to make sure the drain pipe is totally clear. What about trying a proper plumbing snake?

[Junodtim]

I have a Quantum RC25, and my kitchen drain was slow also. I used my shop vacuum and sucked two hands full of furniture padding out of the pipe. I do believe there is a cheater vent inside on that line some where. My kitchen drain works best when the RV is level.

[Bob Denman]

Two handfuls of furniture padding?!?
That almost sounds like the start of a mouse nest: but in an impossible place for it to happen.

[Handy]

Regarding the padding, I have been picturing a partial blockage where the drain pipe enters the holding tank, like maybe a temporary plug that was not removed completely, or padding! That is awesome that you found that!
I inserted a steel snake into the pipe and it freely travels to the holding tank where it hits the bottom of the tank and stops, at least it appears to be the bottom of the tank. I attached my shop vac to the pipe sucking air for a few minutes with no results. Then blew air and confirmed the air was blowing out of the roof vent. Since rebuilding and lowering the p-trap, removing the wiring from between the holding tank and the chassis so the tank could rest on the chassis at the low end of the tank, and applying the vacuum, the drain is 50% better than it was but still not as fast as the shower. I have done everything I can and am happy to put it behind me, but have a feeling that if there is something like padding in the drain then it could eventually clear itself.
When I originally cut out the p-trap my first installation leaked at a coupling. Upon inspection, I found that the existing 1.5" abs pipe had a crimp dimple in the side of it that prevented the fitting from sealing properly. I also had noticed that 6" further down the drainpipe there was a coupling and 2 elbows that were bathed in abs glue which looked like an attempt to stop a leak from the outside. I went ahead and cut all that out also and found more of those dimples in the outside of the abs pipe and figured this is what caused the leak problems for the original installation also. Eventually, I replaced 75% of the original drain pipe from the sink to the holding tank and had to locate a non-dimpled section of pipe for my splice. The dimples were from manufacturing I guess.
Also by re-routing the p-trap, I was able to rebuild the 12" drawer below the kitchen sink and replace it with a 16" drawer. They already had 16" guides installed in the cabinet so I was able to get 16" guides for the new drawer and slide it right in!
After owning this Outlaw for less than a month I got a recall notice for an unsafe wiring connection between the batteries and the isolation switch or relay. My dealer is ordering parts from Thor and then will complete the 45-minute repair in a few weeks. During my inspections I found the ground cable from the generator to the chassis to be finger loose at the chassis, never was tightened.
This weekend I am installing the Weldtec 6" lift! I wonder what the dealer will say about that when I go in for the recall work.

[javelin]

Sorry that you have no sink drain speed happiness yet. It would have been interesting to have tried a drain speed test when you had that same sink drain line open under the coach. It would rule out all up stream pipng/AAV etc.



Since your gen ground connection was not tight; and some of the other items mentioned ....you may have purchased the Tuesday after a long weekend built unit. It might be worth your time to check all major electrical connections including transfer switch; AC and DC equipment. It's a PIA but better then getting stranded in the boonies down the road.....or have some smoke generated that is not barbecue intentional.

[Kickstand]

My 2017 29H outlaw is painfully slow kitchendrain. I just chalked it up to sink in slideout and physics.

[Handy]

At the end of my first year, I had only one problem left on this Outlaw that I was unable to solve myself so I took it into the dealer as a warranty item. They sat on it for a month and then when I called to check the status they told me it was fixed. In disbelief, I went in to see what they had done. I stood there with the service advisor and the shop foreman and asked how they determined it was fixed. The foreman told me that he filled the sink with water, watched it drain, and it looked right. He said that they adjusted a zip tie on the drain pipe under the sink to allow an upwards sloping pipe to slope downwards. I called bullshit because I had already rebuilt the drain pipe under the sink in an attempt to find the problem and there was no pipe that was sloped upwards in the 24" fall from the sink to the gray tank. I demonstrated that the proper way to test the drain is to run water down the drain and if water starts backing up into the sink then there is a problem. The foreman got frustrated and left. The advisor was thankful for the education. I told him that they needed to put a camera down the pipe to see what was obstructing it at the transition to the holding tank. Two weeks later it was fixed. They found a curtain of excess ABS cement hanging down from the pipe where it entered the tank. Two-thirds of the pipe was restricted. Somehow, with limited access, they rebuilt this connection to the holding tank to remove the botched factory job. One of the reasons that I replaced the pipes under the sink was because 2 of the ABS joints were slathered in cement, apparently to try and stop a leak. The person that was doing the plumbing work on my Outlaw at the factory should not be doing plumbing on a $100,000 piece of equipment and it is a shame that this happened in the first place.