Have you experienced a slow drain on your Quantum Kitchen sink?

[chunker]

If you look back at post #1 you will see that the first thing I did was go to Lowe's and buy a high quality Studor Vent to replace the cheap one Thor installed. It did not solve the problem. At the time I was not aware of he minimum height above the P-trap requirement so have not yet tried an extension to raise the vacuum breaker. Will look into that but there is not much head room between the pipe and the bottom of the countertop.

I missed that. Just my opinion since I'm not a plumber, but I'd guess the 6 inches is to keep draining water from splashing out the vent. I suspect the main culprit for you is lack of slope in the lines. Something similar was in the Omni XG32 black tank. Gravity toilet and the black tank "stuff" dropped onto a gently sloping portion of the tank floor. That gentle slope theoretically would drop solids and liquids into the main portion of the tank. In practice the solids have a poop party just below the toilet drain and it requires stiring things up with a coat hanger. 2nd time having to do that my GF was threatening to burn the thing and/or never travel in it again . I dumped the POS for not dumping the total "S". Exceptionally poor design and no thought what they were doing. Same situation you have but less messy.

 

[Bob Nodine]

I missed that. Just my opinion since I'm not a plumber, but I'd guess the 6 inches is to keep draining water from splashing out the vent. I suspect the main culprit for you is lack of slope in the lines. Something similar was in the Omni XG32 black tank. Gravity toilet and the black tank "stuff" dropped onto a gently sloping portion of the tank floor. That gentle slope theoretically would drop solids and liquids into the main portion of the tank. In practice the solids have a poop party just below the toilet drain and it requires stiring things up with a coat hanger. 2nd time having to do that my GF was threatening to burn the thing and/or never travel in it again . I dumped the POS for not dumping the total "S". Exceptionally poor design and no thought what they were doing. Same situation you have but less messy.

To break up the poop party below the toilet I use an old awning rod. The wife likes to use a lot of toilet paper and sometimes if we are camped in one spot for several days it will pile up in the down pipe. I installed a valve behind the toilet to shut off the water and then hold the ball open and stick the awning rod down to break up the poop/paper pile. The awning rod has a right angle on the end which does wonders to disperse the mess. I learned long ago to just keep my mouth shut and roll up my sleeves.

 

[chunker]

To break up the poop party below the toilet I use an old awning rod. The wife likes to use a lot of toilet paper and sometimes if we are camped in one spot for several days it will pile up in the down pipe. I installed a valve behind the toilet to shut off the water and then hold the ball open and stick the awning rod down to break up the poop/paper pile. The awning rod has a right angle on the end which does wonders to disperse the mess. I learned long ago to just keep my mouth shut and roll up my sleeves.

But that's a problem that shouldn't occur and no RV should be so mis-designed. When I was looking at the omni, the brochures said it had a macerator toilet. I considered that to be just something else to break and was pleased that it was a gravity. BUT after the third poop-party-stir-up-event I would have appreciated a macerator. The Valencia has the similar curb side toilet location but has a macerator, and a far superior one, not entry level. No party in it.

 

[Bob Nodine]

But that's a problem that shouldn't occur and no RV should be so mis-designed. When I was looking at the omni, the brochures said it had a macerator toilet. I considered that to be just something else to break and was pleased that it was a gravity. BUT after the third poop-party-stir-up-event I would have appreciated a macerator. The Valencia has the similar curb side toilet location but has a macerator, and a far superior one, not entry level. No party in it.

When first got the coach I considered installing a macerator toilet but could not find one that would fit due to the small bathroom and the fact that the toilet sits on a narrow box that serves as a cable chase.

 

[chunker]

When first got the coach I considered installing a macerator toilet but could not find one that would fit due to the small bathroom and the fact that the toilet sits on a narrow box that serves as a cable chase.

With the omni I also looked into it and it would have been quite a job to get power to the site and the appropriate modifications to the plumbing. That system was added to the long list of structural deficiencies that thor had "engineered" into the product and that led to me deciding the "KIT" I had purchased was not something I wanted to keep. There are different ways thor could have made the black plumbing drain without a macerator or putting it on the other side of then RV. My GF has a Crusader 5th wheel and the toilet, a much better brand and model by the way, has a curved sloping section of the drain pipe to deliver the waste to the black tank. When you look into the toilet you of course can't see the bottom of the tank. We never had any issues with it flushing. A few more $ and thor could have done similar but then they would have to spend a few more $ and maybe put a non-entry level toilet in.

 

[Hose hose]

Nope, both sinks have hard PVC drain pipe and are Teed together before the flex line. If you trace back from the Tee the PVC pipe to the vacuum breaker is a straight run with a little slope. The bathroom sink had no problem opening the vacuum breaker. If there is a clog in the section between the vacuum breaker and the Tee I would think it would also slow the bathroom sink. It might have something to do with the level drain from the sink to the vacuum breaker. See photo below.

My quantum KW29 has the same problem. As others have hinted at, the problem is there is no tail piece (a section of pipe) between the strainer outlet and the P-trap. A section of pipe increases the head pressure on the trap which causes it to empty faster. There is room to insert a tail piece but then the outfall pipe (pipe coming out of the trap discharge side and connecting to pipes leading to the grey tank) must also be lowered so that the water can run downhill. But the way the discharge pipe enters the plumbing to go into the gray tank, there is very little room to lower it much meaning your tail pipe can’t be very long at all. Which brings us back to insufficient head coming out of the sink to flush the P-trap. .

 

[Hose hose]

But that's a problem that shouldn't occur and no RV should be so mis-designed. When I was looking at the omni, the brochures said it had a macerator toilet. I considered that to be just something else to break and was pleased that it was a gravity. BUT after the third poop-party-stir-up-event I would have appreciated a macerator. The Valencia has the similar curb side toilet location but has a macerator, and a far superior one, not entry level. No party in it.

The key to no poop pile is flooding the black tank with about 5 gal water before using it. Poop and paper tend to stick to a tank with no water in it but can’t stick as easily when it’s wet.

 

[Hose hose]

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